Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/22/17

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
822 PM MDT Fri Jul 21 2017 .UPDATE... Added pops to portions of the east central for tonight as isolated thunderstorms have developed from Lea into Roosevelt county most likely spawned by the outflow boundary from storms farther south. Recent RAP13 picked up on this activity and hangs onto it until after midnight, while the HRRR has not yet latched onto anything in that part of the forecast area. Updated ZFP has been transmitted. && .PREV DISCUSSION...521 PM MDT Fri Jul 21 2017... .AVIATION... 00Z TAF CYCLE Plume of moisture stretching from south to north over western and central NM with drier air over the northeast and east central parts of the state. Mts occasionally obscured in brief MVFR cigs/vsbys associated with sct tstms over central and western NM til around 03Z then transition to mid clouds with sct showers. Wind gusts to around 40kt associated with the stronger storms. Upper high center to the east of NM to weaken with the high center over the Great Basin regaining dominance next 24 hrs, which will result in moisture and convection starting to work into the east aft 22/18Z while redeveloping over the west and central. && .PREV DISCUSSION...315 PM MDT Fri Jul 21 2017... .SYNOPSIS... Much of eastern NM will remain dry today and Saturday, but showers and thunderstorms will persist across western and central New Mexico. Locally heavy rain and areas of flooding will be possible. Storm coverage is expected to increase area wide on Sunday after a boundary slides down the plains and through the gaps of the central mountain chain Saturday night. Heavy rain and flash flooding will remain a threat. Thereafter, the upper level high will build over New Mexico, decreasing the chances for storms through the middle of the week. && .DISCUSSION... Abundant dry air remains in place over eastern NM this afternoon, relegating showers and thunderstorms to central and western NM. So far, a rather tame set of storms given near 0.99" PWAT on the 12Z ABQ sounding, and an MCV over the southwest mountains and another over NE AZ. Additionally, satellite imagery is showing the moisture plume getting squeezed between the persistent ridge to the east, and developing ridge to the northwest. With the plume becoming more focused, combined with the other aforementioned reasons, expect at least western NM to become more active through the early evening, with areas of flooding possible. Rainfall rates could exceed 2"/hr. On Saturday, the ridge to the east of NM will weaken, while the high to the northwest will strengthen. Meanwhile, the dry air that is over eastern NM today, may actually advect a bit westward across central NM around the strengthening high. So, it`s not looking like as much of an uptick on Saturday as previously thought. However, it does appear that the northern mountains will remains quite active, as well the southwest mountains. PWATs won`t change much overall, perhaps slightly less, so locally heavy rains will remain possible in these areas. Saturday night should see an increase in activity at least across northeast NM. A boundary across Colorado will push southward into the plains, convectively aided. This boundary will be a focus for precipitation on Sunday, though the NAM and the GFS are a bit at odds with regards to how far south and west this boundary will go. Will hedge closer to the NAM as it is more in line with the ECMWF. Therefore, there should be plenty of upslope flow across the plains on Sunday and storms should initiate over the central mountain chain and spread across at least the northeast plains. Storms may stay closer to the high terrain across the southeast, but that will depend on if there are any remnant boundaries from the previous nights convection. Meanwhile, the high terrain of western NM should remain active. All-in-all, this may be the busiest day of the next several. PWATs look to increase some as well, so the potential for flash flooding remains. On Monday, the upper high that was to the northwest of NM will build right over NM. This will result in less convection, though the mountains will remain active. The high will remain over NM through at least mid week, thus lesser storm coverage is expected each day. There will still be storms, but relegated mainly to the mountains. Could see an increase in storm coverage late in the week if the upper high can shift a bit eastward. 34 && .FIRE WEATHER... A thin axis of deeper moisture centered over central and western NM will be the focus for the best coverage of showers and storms with wetting rainfall through the weekend. Storm motions toward the north and northwest today will shift more toward the northeast and become slow and erratic toward the southeast through Sunday. Locally heavy rainfall with flash flooding is possible mainly for the northern and western high terrain, especially areas that receive multiple rounds of rainfall. A couple models are trending drier for the southeastern half of the region this weekend. The frontal boundary advertised to shift out of Colorado doesn`t look as robust and a very dry mid and upper level airmass to our east is maintaining a tight grip over eastern NM. Temperatures will remain hot across the east while readings across the west trend near to below normal. Weaker flow aloft will favor deteriorating ventilation through the weekend all areas. There are even more notable changes from models the past 18 hours that will impact precipitation coverage next week. A dry and hot upper high center to the east of NM and another gathering strength over the Great Basin are now shown to choke the moisture plume and shift the pool of moisture into southwestern NM and AZ beginning Tuesday. As a result, temperatures have trended warmer through next week for central and eastern NM while the focus for greater storm coverage shifts into far western NM and AZ. Ventilation in this pattern will remain poor/fair for most of the region. Guyer && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service State College PA
1024 PM EDT Fri Jul 21 2017 .SYNOPSIS... Pennsylvania will be on the northern periphery of a subtropical ridge passing across the southern states through the weekend. A few rounds of showers and thunderstorms are expected both Saturday and Sunday, and some could produce gusty winds, hail and heavy downpours. Another cold front will push through the area early next week. && .NEAR TERM /UNTIL 8 AM SATURDAY MORNING/... A boundary dropping southward through PIT is firing off convection. Dewpoints on one side are in the m60s, and KPIT is 76F. Don`t see that too often in PA. Some of this convection could slide into the Laurels shortly, but HRRR & RAP - which, to their credit, do have it there - die it off. Have just mentioned a shower there through 2-3AM. Dewpoints are high, sky only partly cloudy, and the air is calm. Fog already in fcst for some places, and have added fog to the rest of the area, mainly in the valleys. All the rest of the forecast is in great shape. It was a dark and muggy night... Prev... Convection all but dead. Just a hint of taller cu in the far srn tier, and the 20 POPs there will expire in an hour or so - right on time. Other than the high clouds in the N, clearing should come to much of the area shortly. Prev... Weakening MCS traversing WV and approaching the WV and MD panhandles at mid afternoon. PW pooling around 2" along the Mason Dixon line and slowly lifting northward should bring isolated to scattered coverage of showers and thunderstorms through this evening across my southern tier counties (Laurel Highlands and South Central Mountains), with mainly dry conditions expected elsewhere. remnants of aforementioned MCS track off the mid Atlantic coastline later this evening, and any diurnally-driven showers or storms along the southern tier should die out around sunset. Weak surface ridge passes over PA tonight bringing fair weather and mins ranging from the upper 50s north to around 70 southeast. && .SHORT TERM /8 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... Large MCS forms upstream overnight and approaches eastern OH in the pre dawn hours Saturday morning. This feature will be the main player for potential severe weather on Saturday, as strong moisture flux and increasing boundary layer convergence point increase the likelihood of strong to severe storms over PA by late morning and afternoon. CAMs differ on timing and strength of MCS evolution ranging from as early as late morning into my western zones to as late as mid to late afternoon. Think the former is more likely...given quick moisture return late tonight and Saturday ahead of the approaching complex. Warm front pushing into the region on Saturday will also tend to favor lower LCLs and sufficient shear for rotating updrafts. Farther north, extensive cloud cover associated with the warm front will likely result in limited CAPE Saturday as the 00Z GEFS shows. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... A second round of convection is possible Sat night as strong low level jet and plume of anomalous PWATs works through the area. Convection associated with this feature could potentially evolve into another MCS with potential for overnight severe weather in central PA into Sunday morning. Favorable scenario for additional severe weather across central Pa during the daylight hours Sunday as the region will be within warm sector south of anomalous surface low tracking eastward along the PA/NY border. Moderate CAPES and moderate westerly flow aloft, combined with large scale forcing ahead of approaching upper trough, should support widespread convection by afternoon. Some uncertainty continues with regards to timing of upper trough passage early next week, but additional showers/storms appear possible. A period of dry and cooler weather appears very likely by midweek, as upper trough axis finally passes east of Pa and surface high builds into the area. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... Quiet night tonight, with most locales remaining VFR, though the usual spiderweb of valley fog will settle into the western and northern mtns. The warm air and high dewpoints will allow for fog formation early, which will mean IFC cigs will form between 04Z to 08Z. Expect them to continue until 12Z to 13Z. Mainly partly sunny skies with increasing clouds through the day with CIGS dropping to MVFR between 18Z to 21Z with showers and thunderstorms in the vicinity of TAF sites after 18Z progressing west to east as a warm front pushes into the region. This will be followed by an upper trough on Sun, which will keep numerous showers and thunderstorms around over the weekend. .OUTLOOK... Sat...AM valley fog possible. TSRA/SHRA likely with intermittent impacts. Sun...AM valley fog likely. Cig restrictions likely north. TSRA/SHRA likely with intermittent impacts. Sun night...Cig restrictions likely. Scattered TSRA/SHRA. Mon...AM restrictions likely. Scattered TSRA. Tue-Wed...Patchy AM fog. Otherwise no sig wx. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...DeVoir NEAR TERM...Dangelo/DeVoir SHORT TERM...DeVoir LONG TERM...Fitzgerald/Gartner AVIATION...Ceru
Area Forecast Discussion
National Weather Service Duluth MN
715 PM CDT Fri Jul 21 2017 .UPDATE... Issued at 715 PM CDT Fri Jul 21 2017 Severe thunderstorms were occurring this evening from just north of Duluth west through the Grand Rapids area into the Pine River area. Instability has been steadily increasing across the Northland and the storms have shown little signs of weakening as they move toward a less unstable airmass to the east. The afternoon KINL sounding showed dry air in the lower to mid levels which will enhance the wind threat. Per coordination with SPC, we`ve added Aitkin, Carlton, and Saint Louis Counties to the watch. The latest HRRR shows the storms continuing for the next few hours but gradually decreasing in intensity as they move further east. && .SHORT TERM...(This evening through Saturday) Issued at 336 PM CDT Fri Jul 21 2017 Storms have formed over northwest Minnesota this afternoon that we have been watching very carefully. A severe thunderstorm watch has been issued, and I will leave it to the reader to refer to the specifics of that watch in the WCN. A plume of 2000J/KG plus most unstable CAPE extends up the Red River valley, overlapping much of western Minnesota and eastern North Dakota and South Dakota. In addition, this area has decent shear, a weak shortwave aloft and is underneath the right entrance region of the upper level jet. We are looking at getting a round of severe storms for the next few hours, mainly affecting the far western areas of the CWA along the high cape gradient. After that have poor confidence in additional storms, though several models bring a second round of convection through the southwestern half of the forecast area after midnight tonight. Attention then turns to Saturday, when the tight upper low/vort max currently over the Saskatchewan/Manitoba border drops southeast cross the forecast area during the afternoon and early evening. Expect that depending on the overnight convection we will have an additional round of showers and thunderstorms move across the area during the afternoon and early evening. Depending on the amount of CAPE we can develop severe weather is a real threat, but we will have to watch what happens overnight tonight to determine the daytime threat for tomorrow. .LONG TERM...(Saturday night through Friday) Issued at 336 PM CDT Fri Jul 21 2017 The extended forecast period features a couple of chances of showers and thunderstorms over the Northland, with temperatures forecast to remain around seasonal averages. Saturday night begins with continuing chances of showers and storms from Saturday afternoon as a compact mid-level shortwave dives across our north and eastern areas of the CWA Saturday night. There should be some good forcing associated with this shortwave as there is a large lobe of positive vorticity advection, along with higher 850-300 mb omega, per the Thaler QG analysis. The Storm Prediction Center currently has the entire Northland in a Slight Risk of severe weather for the Day 2 convective outlook. The magnitude of instability from 00z Sunday between the synoptic models differs somewhat, with values ranging between 300 up to 2000 J/kg between the GFS/NAM/ECMWF/CMC models. The expectation is that any strong to severe convection on-going at 00z Sunday will dissipate as the sun sets, decreasing instability rapidly. There could be some damaging winds and large hail possible, if some strong convection continues into this period. As the shortwave departs, there may be some lingering showers Sunday morning as the region remains under the cyclonic flow of the mid-level wave. Non-zero MUCAPE could provide enough instability for a rumble of thunder, but no severe weather expected at this time. By Sunday afternoon, drier conditions will return to the Northland, as sfc high pressure builds. Skies look to clear out overnight Sunday into Monday morning, so there could be some patchy fog, especially over areas that receive rainfall Sunday. Winds look to be light as well, especially over the Minnesota Arrowhead and along Lake Superior. Dry conditions will continue through the day Monday before another area of low pressure develops over northern Manitoba and northwest Ontario Canada, bringing a cold front boundary through the Northland. The GFS/ECMWF/CMC models are showing some decent agreement with the areal coverage and timing of precipitation, so confidence is fairly high this precipitation will move through Tuesday morning and afternoon. Temperatures will be around seasonal averages, with highs in the 70s across the Northland. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 715 PM CDT Fri Jul 21 2017 Strong to severe storms were occurring across portions of the Northland this evening and they will continue to move east. IFR or LIFR conditions will occur in and near the storms along with strong winds and hail. Outside of the storms, expect mainly VFR conditions this evening but IFR or MVFR ceilings will expand later tonight into Saturday morning before lifting to VFR. Additional showers/storms will be possible through the night and again Saturday as a frontal boundary and upper level trough impact the area. Updates to the chance for storms will be needed as we progress through the period. && .PRELIMINARY POINT TEMPS/POPS... DLH 59 73 57 70 / 50 40 40 20 INL 60 77 56 74 / 40 60 40 20 BRD 65 83 60 75 / 50 10 10 10 HYR 63 80 58 71 / 20 40 30 20 ASX 58 74 56 67 / 10 30 30 30 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement until 8 PM CDT this evening for WIZ001. MN...Beach Hazards Statement until 8 PM CDT this evening for MNZ037. LS...None. && $$ UPDATE...Melde SHORT TERM...LE LONG TERM...JTS AVIATION...Melde
Area Forecast Discussion
National Weather Service Flagstaff AZ
310 PM MST Fri Jul 21 2017 .SYNOPSIS...Expect very active monsoon conditions for the next several days. Local heavy rainfall capable of producing flash flooding remains possible from stronger storms. && .Discussion...Another active day across northern Arizona today. Storms are generally moving from northwest to southeast and producing locally heavy rain and flooding issue--especially over recent fire scars. A few storms also show (on radar) indications of one inch or larger hail. Showers and thunderstorms will decrease in coverage after dark tonight. However, other storms/storm clusters could develop overnight. HRRR is showing the Northeast and White Mountains as the favored areas for development overnight. For Saturday and Sunday...The forecast models are still insisting that a northeast to southwest flow sets up across Arizona in response to high pressure becoming centered over Nevada/Utah/Arizona. The described flow pattern will deliver a drier air mass to the northeast corner of Arizona with a decrease in shower and storm activity. From the Mogollon Rim and White Mountains southward and across central Arizona monsoon moisture will remain entrenched with a good chance of showers and storms each day. From Monday onward...Moisture will remain in place with the threat for daily showers and thunderstorms continuing. && .AVIATION...For the 00Z package...Expect scattered to numerous SHRA and TSRA lasting into early evening, with isolated +TSRA. MVFR/IFR in the stronger storms. Shower and thunderstorm coverage gradually decreasing after 03Z. Other thunderstorm development is also possible through the night. More storms are expected again after 17Z Saturday. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Active monsoon conditions will continue through Saturday with scattered to numerous showers and thunderstorms. Heavy rain and gusty winds will remain the primary impact. Expect near average temperatures across the area. Monday through Wednesday...Daily chances for showers and thunderstorms continue, favoring the Mogollon Rim southward Sunday, then all of northern Arizona Monday and Tuesday. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MAS AVIATION...MAS For Northern Arizona weather information visit
Area Forecast Discussion
National Weather Service Grand Rapids MI
947 PM EDT Fri Jul 21 2017 LATEST UPDATE... Update .SYNOPSIS... Issued at 815 PM EDT Fri Jul 21 2017 An area of low pressure will track eastward along the quasi- stationary front just south of Michigan tonight into Saturday. It will keep most of the strong storms closer to I-80 than I-94. There will be some periods of light rain tonight over areas near and south of Grand Rapids with the risk of thunderstorm around midnight west of Battle Cleek, near and south of I-94. A few instability thunderstorms are possible Sunday and the truly cooler air moves into the area. Canadian high pressure will move through the area early next week bringing slightly cooler than normal temperature and considerable sunshine. && .UPDATE... Issued at 946 PM EDT Fri Jul 21 2017 The thunderstorm complex continue, for the most part, tracking southeast. Watching the individual cells in the storm complex over WI, IA, IN and IN most of the cells are tracking southeast too. However over the past 1/2 hour one cell just south of the city of CHI is tracking northward. Likely this is some sort of boundary interaction. On the other hand the RAP and HRRR low level jet shows a surge northward just ahead of the MCV assoicated with the complex of storms near CHI moves across Southern Lake Michigan and Northern Indiana over the next few hours. It is more than possible a few storms could make it into Van Buren and Kalamazoo Counties in the 11 pm to 2 am time frame. Otherwise near and north of I-96 it would seem to me there little if any threat for thunderstorms tonight. The way the surface wave tracks across the CWA Saturday it would seem the instability will stay south of I-94 most of the day. I see very little chance of showers so I lowered the POP over most of the area through the afternoon. UPDATE Issued at 815 PM EDT Fri Jul 21 2017 It seems to this forecast that the threat for any serious severe storms is once again been trumped by the frontal boundary being closer to I-80 than I-96. While there is a real surface wave on that front, and that will allow some storms to track east to east southeast just north of the warm front, that warm front does not really push northward into our area overnight. That tells me the significant convection will also stay south of our area. Going along with this idea of you look at the SPC-HRRR model browser and look at the trends of models heavy rainfall between 17z runs and the 22z run for any hour between 01z and 09z, the heavy rainfall is father south with each run. So the trend suggest the strongest convection will miss our CWA to the south. The best chance for any thunderstorms would be west of Battle Creek along and south of I-94 between 11 pm and 2 am as the best support moves through this area. As a result I trended back on the precipitation (POP) threat and put the significant QPF significantly farther south. I may have to do cut back on the QPF even farther later this evening. && .SHORT TERM...(This evening through Sunday night) Issued at 330 PM EDT Fri Jul 21 2017 Very high precipitable water values will mean we will have to monitor radar trends for excessive rainfall tonight. The model guidance including the HRRR and NCAR models have trended further south with the higher risk of storms tonight but the southern forecast area may still get clipped by the organized storms which will also bring the threat of strong winds. We have adjusted POPs and QPF further south and lowered POPs on Saturday based on the belief that convection tonight will impede instability and moisture transport on Saturday. .LONG TERM...(Monday through Friday) Issued at 330 PM EDT Fri Jul 21 2017 The weather to start the period will be characterized by a mid level ridge which will be building in from the Upper Plains. This feature will help to dry the airmass out and lead to a cooling trend with the temperatures. Will feature dry conditions for Monday and Tuesday as the surface high tracks through. Mid level height falls occur over the Great Lakes region as we go into Wednesday and Wednesday night. This will be the result of an upper low that will be tracking eastward from Ontario into Quebec. Models are in reasonable agreement on the timing and track of this system. Thus some showers look possible ahead of and along the cold front associated with this system With instability developing as well... a risk for a few storms exists. Overall the forecasted forcing and instability look will only go with a low chance for measurable precipitation. The atmosphere then dries out for the end of the week as a northwest flow and subsidence develops behind the departing front. The new High Res Euro does stall the front out just south of the MI border on Thursday and tracks a weak surface wave along it. If this system trends further north with time...some rain may occur for southern parts of the CWA. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 815 PM EDT Fri Jul 21 2017 For the most part the convective threat is south of our TAF sites tonight. Still I could see, being north of the surface wave tracking along the front to our south, there will be an area of low clouds and light fog Saturday morning. This should clear by mid afternoon but that will not be long enough to allow enough instability for afternoon thunderstorms. My bottom line to this is VFR most of the night (threat of thunderstorms best at AZO after 05z). The other TAF sites are to far east or north to be impacted by this event. && .MARINE... Issued at 330 PM EDT Fri Jul 21 2017 Winds and waves will generally remain relatively light through the weekend. The exception could be for some gusty winds and higher waves tonight in strong thunderstorms south of Muskegon and Saturday morning south of of South Haven. There could be some dense fog at times through Saturday before drier air moves in. && .HYDROLOGY... Issued at 330 PM EDT Fri Jul 21 2017 The favored region for locally heavy rainfall through early Saturday will be south of I-96 and particularly near the MI/IN border. Hi res models have trended further south with thunderstorm activity overnight into Saturday morning due to poor handling of earlier convection. Therefore, the risk for heavy rainfall has shifted accordingly. Localized flooding will still be possible where any storms persist. This may be more of a concern near I-94 and toward the MI/IN border. Rises of small rivers and streams will be possible but it is not looking like the main stem rivers will have any big issues unless convective trends change significantly. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...None. && $$ UPDATE...WDM SYNOPSIS...WDM SHORT TERM...Ostuno LONG TERM...MJS AVIATION...WDM HYDROLOGY...Hoving MARINE...Ostuno
Area Forecast Discussion
National Weather Service Wilmington OH
948 PM EDT Fri Jul 21 2017 .SYNOPSIS... Multiple disturbances are expected to bring several rounds of showers and thunderstorms to the region through the weekend and into early Monday. High pressure and dry conditions are then expected for Tuesday. More disturbances in northwesterly flow aloft will cross the region later in the week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... A very humid air mass remains in place over the ILN CWA, with the 00Z KILN sounding indicating an unstable and uncapped environment. Forcing has been the missing factor through most of the day, though a few isolated storm clusters developed near Cincinnati, and a weak boundary (part of a tailing boundary from an earlier MCV) is now starting to ignite near Wilmington. Nonetheless, with overall support for organized ascent rather weak, and no shear to speak of, activity through the first half of the overnight is not expected to be more than intermittently strong (and unlikely to be severe). A much different scenario is expected for the second half of the overnight period, as an environment much more favorable for organized storms gradually advects to the ESE out of northern Illinois. The thermodynamic environment over the ILN CWA (and downstream of existing convection) will be entering its usual min, which may lead to some storms becoming elevated with time, as indicated by RAP/HRRR soundings. What these storms will bring is their own source of forcing (low level convergence ahead of another developing MCV) and shear (increasing 30-35 knot westerly 850mb flow). These factors should help the storms stay strong to severe, at least for portions of the line/MCS/cluster, even as the storms make it into the ILN CWA somewhere in the 3AM-6AM time frame. Current storm trajectories, storm-level flow, and recent HRRR runs would suggest the greatest threat for strong storms will be in the northern third of the forecast area. Nonetheless, eventual propagation toward instability will likely lead to more of the area being impacted in some way. PoPs have been increased and re-focused in terms of timing and placement, based on this latest forecast information. Finally, added some fog to the forecast for the areas where heavy rains occurred from Cincinnati southeastward. Previous discussion > Apparent temperatures were expected to remain at or over 100 in the southwest, which had me extend the current advisory into the overnight hours as the eastern portion of it drops off later today. Upstream thunderstorm complex west of Indianapolis and a shower complex underneath the MCV northeast of Indy will work into the CWA later this afternoon into this evening. Expect convection to be possible almost anywhere this evening but with a higher propensity southwest of a Richmond/Lebanon/Georgetown line. Overnight should see convection from this evening waning, but another upper level disturbance will ride southeast in the mean flow and cross northern Ohio. Storms from this will primarily affect the I-70 corridor and northward, with isolated activity possible elsewhere late overnight. Confidence in the occurrence and/or placement of these storm clusters is low. Forecast will be dynamically updated as storms fire and a better timing and areal extent of them are able to be extrapolated in both time and space. With this being said, forecast is probably too low on pops overnight in the northern CWA where it was limited to chance category. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... Saturday had me bring another tier of counties into the heat advisory fold as unusually warm dewpoints solidly in the middle 70s combine with temperatures in the low 90s to push apparent temperatures over the 100 degree mark. Storms that are present in the morning should be focused north of and along the I-70 corridor, but a few models are indicating some isolated activity popping south of it just before daybreak. The outflow boundary that lays out along the I-70 corridor later in the day is expected to be a focus for a second round of development, given an added boost by a continued feed of moist and unstable air on southerly winds. Storms will fire along a w-e oriented line and then move south in the evening. Any storm in the next few days will have a higher potential for damaging winds and especially very heavy rainfall. The tornado and large hail threat appear to be negligible at this moment in time. Storms will weaken and diminish as they move south to the Ohio River on Saturday night. Dewpoints will remain in the middle 70s until the airmass changes beyond the short term period. && .LONG TERM /SUNDAY THROUGH FRIDAY/... A weak trof/boundary is forecast to push through the region on Sunday. This feature may be entering our far eastern/southeast zones by peak heating which would bring the highest PoPs to these locations. All in all, just have slight chance/chance of showers/storms. SPC has a slight risk for severe storms. There could be an isolated severe during the afternoon due to diurnal heating. For the period Sunday night into Monday night, mid level trough will dig southeast across the Great Lakes/eastern Canada. As this occurs, a cold front will move slowly southeast through our region. With the lack of strong low level forcing and upper level support, the chances for showers/storms appears low and should affect our eastern/southern zones in the afternoon on Monday. Skies should become at least partly cloudy Monday night as high pressure builds into the region from the north with a drying and stabilizing air mass. High pressure should remain over the region through at least Tuesday into Tuesday night with dry weather expected. As the high moves east on Wednesday, return flow and increasing moisture may lead to a small chance of showers and thunderstorms. Models indicate that the next frontal boundary to affect our region will be during the Thursday/Friday time frame. Differences are seen in the timing, so a broad brush forecast has been used with a chance of showers and thunderstorms. Temperatures will cool back down to more July normals Tuesday through Friday. && .AVIATION /02Z SATURDAY THROUGH WEDNESDAY/... While VFR conditions will prevail through the evening, an area of thunderstorms will move through the Cincinnati area over the next hour or two, possibly bringing MVFR/IFR TSRA conditions to the CVG/LUK TAF sites. Some MVFR visibilities are possible with an area of rain moving into CMH/LCK as well. Later in the overnight period, a larger complex of thunderstorms is expected to move into the region, affecting the northern four TAF sites near daybreak. These storms have now been specifically included in the TAFs, and future forecasts may need to forecast further reduced conditions (lower ceilings / higher winds) with the storms. It is most likely that these storms will remain north of Cincinnati. Outside of the storms, some MVFR visibilities are also possible at the Columbus airports. After a break in the activity through late morning and early afternoon, additional thunderstorm development will be possible going into the afternoon and evening. Southwest winds will increase to around 10-15 knots. OUTLOOK...Thunderstorms will be possible again from Saturday night through Sunday, and then again on Wednesday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...Heat Advisory from 1 PM to 7 PM EDT Saturday for OHZ070-071. Heat Advisory until 7 PM EDT Saturday for OHZ077-078. KY...Heat Advisory until 7 PM EDT Saturday for KYZ089>096. IN...Heat Advisory from 1 PM to 7 PM EDT Saturday for INZ066. Heat Advisory until 7 PM EDT Saturday for INZ073>075-080. && $$ SYNOPSIS...Franks NEAR TERM...Franks/Hatzos SHORT TERM...Franks LONG TERM...Hickman AVIATION...Hatzos
Area Forecast Discussion
National Weather Service Lincoln IL
901 PM CDT Fri Jul 21 2017 .UPDATE... Issued at 901 PM CDT Fri Jul 21 2017 Current forecast grids have already been updated once, but will be making further adjustments to mainly pops/wx and severe watch. All convection has remained north of the CWA this evening and based on current radar trends looks like it will remain north of the CWA remainder of the evening and possibly into the overnight hours. However, additional precip is expected to develop along the boundary out west and then move into northern IL again overnight. Convection therefore is still possible in northern part of the CWA overnight and will maintain some pops up there. Will be making adjustment to evening pops across the north to account for current trends. Update should be forthcoming. && .SHORT TERM...(This evening through Saturday) ISSUED AT 300 PM CDT Fri Jul 21 2017 19z/2pm surface analysis shows a 1006mb low over northeast Nebraska...with a warm front extending eastward along the I-80 corridor. A large cluster of showers/thunderstorms has been ongoing throughout the day northeast of the low over southeast Minnesota into Wisconsin. As a result, an impressive instability gradient has developed from north to south across Iowa, with SBCAPEs of 5000-6000J/kg south of the boundary in southern Iowa. A new cluster of storms has recently developed along this boundary near the Iowa/Nebraska border. The HRRR has been consistently showing convection firing in this area for the past several runs, with the storms then developing/tracking E/SE along the boundary into north-central Illinois this evening. Given the extreme instability feeding into the storms, think they will quickly form robust updrafts and become severe across central Iowa over the next couple of hours. Once a cold pool can develop, the storms will then begin racing E/SE along the instability axis into north-central Illinois by mid to late evening. While the main push will likely be along the I-80 corridor, think areas as far south as I-74 will feel the impacts as well. Based on latest HRRR, have introduced likely PoPs across the NW KILX CWA around Galesburg by 02z/9pm. Have then spread likely PoPs E/SE along/north of I-74 into the overnight hours. As the initial convective system pushes east, a trialing band of showers/thunder will gradually sink southward to I-72 toward dawn Saturday. Further south, have kept the southern half of the CWA dry through the entire night. As it stands now, think the biggest threat for severe weather and potentially damaging wind gusts will focus along/north of I-74 between 9pm and 3am. Scattered showers and thunderstorms will linger across the northern CWA through mid-morning Saturday before dissipating. May see some re-development along the cold front later in the afternoon: however, subsidence in the wake of the morning convective system may act to suppress widespread development initially. As a result, will only carry low chance PoPs during the afternoon. Areal coverage of convection will likely increase across the southern half of the CWA Saturday evening as the front sinks further south. High temperatures on Saturday will once again climb well into the 90s...with peak afternoon heat index readings of 105-115 degrees. .LONG TERM...(Saturday night through Friday) ISSUED AT 300 PM CDT Fri Jul 21 2017 Front will sink into the Ohio River Valley on Sunday: however, a trailing weak trough axis may trigger isolated thunderstorms. Once this feature passes, high pressure will build into the region early next week...allowing a cooler/less humid airmass to take control. High temperatures will drop into the lower to middle 80s for both Monday and Tuesday, then will slowly climb back into the middle to upper 80s by Wednesday. There are still some discrepancies among the synoptic models later next week, but consensus suggests the next significant chance for rain will hold off until late Wednesday night through Friday as a slow-moving frontal boundary comes into the picture. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 646 PM CDT Fri Jul 21 2017 Main short-term aviation concern will be convective trends through the evening. Latest radar imagery continues to show a cluster of thunderstorms over eastern Iowa, moving E/SE along a stationary frontal boundary draped across northern Illinois. Based on radar timing tools, it appears these storms will remain north of the I-74 terminals later this evening. Once this initial surge of storms passes to the north, trailing cells will gradually settle southward overnight into early Saturday morning. As a result, have introduced VCTS at KPIA/KBMI/KCMI between 09z and 14-15z. A cold front will drop into central Illinois on Saturday, triggering scattered thunderstorms by late afternoon. Based on expected location of boundary at peak heating, have included VCTS at KSPI/KDEC after 21z. Winds will initially be from the S at less than 10kt this evening, then will veer to the W/NW by Saturday afternoon as the front arrives. && .ILX WATCHES/WARNINGS/ADVISORIES... Excessive Heat Warning until 8 PM CDT Saturday for ILZ027>029- 036-037-040>042-047>054-061-062-066>068-071>073. Heat Advisory until 8 PM CDT Saturday for ILZ030-031-038-043>046- 055>057-063. && $$ UPDATE...Auten SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Barnes
National Weather Service Jackson KY
1044 PM EDT Fri Jul 21 2017 .UPDATE... Issued at 1044 PM EDT FRI JUL 21 2017 Another cluster of showers and thunderstorms developed further north of the area, along the outflow from the earlier convection this evening. The remnants of this, have been spreading some light rain across our far northeast counties. Have held onto some some isolated showers over the next hour or so, as this remnant gradually diminishes off to the east, while any new convection initiates further northeast into southern Ohio. Otherwise, mostly clear skies reign south of I-64, with temperatures ranging from the mid 70s in the cooler valleys, to the lower 80s in some of the broader valleys and ridgetops. Organized convection upstream in Illinois and Indiana will spread some high clouds near and north of I-64 by around 06z and thereafter, but the associated precipitation continues to look to stay north of our area through the overnight. Updates have been sent. UPDATE Issued at 758 PM EDT FRI JUL 21 2017 Isolated convection initiated north of I-64 early this evening. This is on the demise now, as outflow from earlier storms gradually lifts to the northeast. Ongoing more organized convection up in Illinois looks to stay to our north through the rest of the night, so will keep the area dry. Consequently, have reduced the sky cover and played up the valley fog a bit more. Lows generally in the low to mid 70s looks on target, although did nudge a few valley readings down a bit more based on the trends in observations. Updates have been sent. && .SHORT TERM...(This evening through Saturday night) Issued at 325 PM EDT FRI JUL 21 2017 Convection associated with the MCS that moved across OH affected the northern part of our forecast area this morning, but the convection quickly dissipated as it moved into the northern part of our forecast area. A couple of outflows were associated with this with one pushing into VA where more convection was triggered, and a secondary residual boundary which remains across the central part of the forecast area. It is still possible something could develop along this residual boundary late this afternoon and evening. Satellite also shows an MCV across IN with convection beginning to develop in west central IN, and there is yet another MCS across WI. The HRRR is not showing much development this evening over IN with the MCV, but latches onto the system now in WI. Both the NAM and GFS point towards the possibility of convection across the north early tonight, possibly associated with the Indiana MCV. The ECMWF points towards a chance in the north closer to dawn as the main MCS now in WI passes by to our north. For the near term forecast have leaned towards the HRRR with support from the ECMWF. This results in lower rain chances for tonight than either the GFS or NAM MOS. As we move into Saturday another steamy day is on tap with maximum forecasts mostly in the lower 90s and heat indices near 100. How much convection we see on Saturday is still in question and followed the standard model blend for rain chances Saturday. .LONG TERM...(Sunday through Friday) Issued at 325 PM EDT FRI JUL 21 2017 The period begins with a upper level short wave trough and associated surface low pushing SSE across the northern Great Lakes. This will progress on into the northeastern U.S. early next week, with the associated cold front moving across our area on Monday. At this point it appears the best chance for showers and storms will be Sunday afternoon even though the front won`t clear the area until Monday. The front looks to stall to our south next week. This will result in temperatures closer to normal, but with at least a small chance of daily showers and storms especially in the southern part of the forecast area. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 758 PM EDT FRI JUL 21 2017 Mainly VFR conditions will prevail through the period, as we remain under the influence of an upper level ridge. Some MVFR or worse fog will be seen in the deeper valleys once again between 06 and 12z. Some relatively drier air did mix down at SME and LOZ late this afternoon into the early evening hours. As such, have only kept a temporary window of MVFR fog at SME to between 09 and 12z. Isolated to scattered convection will threaten eastern Kentucky during the afternoon hours, and have included VCTS at all sites by 16z Saturday. Light and variable winds through the night will increase to between 5 and 10 kts out of the west southwest by Saturday afternoon. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...SBH LONG TERM...SBH AVIATION...GEOGERIAN
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
729 PM CDT Fri Jul 21 2017 .SHORT TERM...(This evening through Saturday) Issued at 307 PM CDT Fri Jul 21 2017 The model consensus of the RAP, HRRR, NAM and HRRR exp appear to be keying on a disturbance moving through Ncntl Colo as the forcing for storm development across Swrn Neb this evening. WPC has put Ncntl Colo on notice for heavy rainfall potential and what develops out west should grow upscale into Swrn Neb tonight. The HRRR appears to generate heavy storms from the robust CAPE across Ncntl Neb. This instability forms ahead of a cold front moving through Ncntl Neb which could form a strong cluster of thunderstorms late this afternoon and this evening. 850mb winds this evening become northeast and this should support upslope theta-e advection into Colorado supporting the model consensus and the WPC heavy rain discussion. This storm activity would be late evening and overnight across Swrn Neb. Precipitable water will be 1.5-1.75 inches supporting locally heavy rainfall. Thunderstorms may redevelop Saturday afternoon across Swrn Neb. The stronger storm activity could easily be across Scntl Neb near the Sfc front but h850mb winds are east across Swrn Neb which could support storms near and south of Interstate 80. The temperature forecast tonight uses blended bias corrected guidance for lows mostly in the 60s. Blended guidance plus bias correction produced highs in the upper 80s to mid 90s Saturday. .LONG TERM...(Saturday night through Friday) Issued at 307 PM CDT Fri Jul 21 2017 Whatever rain activity that forms Saturday should move south Saturday evening. Moisture decreases markedly by Sunday morning but begins to increase Monday as return flow develops. Opportunities for thunderstorm development Monday through Friday revolve around genesis off the Black Hills and Laramie Range. The subtropical upper level ridge retrogrades Sunday and Monday setting up northwest flow aloft. Storm development could be off the Black Hills Monday. Thereafter, the upper level ridge builds east and a ridge runner pattern sets taking storms through SD, perhaps affecting Nrn Neb. POPs are lofty in the 30 to 40 percent range which could be a stretch given the drought conditions underway. POPs across Wrn Neb are mostly isolated which is appropriate given the developing thermal ridge and associated capping mechanism. The temperature forecast uses bias corrected model data from the ECM, GFS and GEM. This was close to the national blend of model and guidance data. Highs in the 90s will be common. The upper level ridge will build back toward the cntl Plains Tuesday through Thursday presenting a potential heat wave. H700mb temperatures rise to 14-16C during this time. The models have been slow to adjust with temperatures. The GFS gives 90s to near 100 for highs those days. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 726 PM CDT Fri Jul 21 2017 Isolated strong to severe thunderstorms between KODX and KONL in north central Nebraska this evening. Baseball hail reported with the southern storm. Storms to move out of northeast Colorado through the early morning hours of Saturday. Have carried vcts at KLBF. && .LBF WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM CDT /7 PM MDT/ this evening for NEZ005>010-025>029-037-038-059-070-071. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Power
Area Forecast Discussion
National Weather Service Melbourne FL
905 PM EDT Fri Jul 21 2017 .UPDATE... Tonight...The early onset of convection has resulted in an early end. The GFS shows high moisture remaining over the area, but the evening soundings actually look a little drier than the model. The GFS only generated light precip overnight while the HRRR indicates a dry forecast. Have already updated the forecast to take out POPs for the overnight period. && .AVIATION...VFR until convection initiates tomorrow. Don`t see any sources of subsidence/drying so expect the atmosphere will remain very moist. The east coast sea breeze development early in the afternoon should start things off again, so have vicinity thunder at the coastal terminals at 17z. Boundary interactions will then build storms inland and have vicinity thunder at the interior sites at 18z. Some drier/cooler mid level air should promote a potential for strong wind gusts and frequent lightning strikes. && .MARINE... Tonight-Sat...Suppressed surface ridge axis will produce a south/southwest gradient wind flow. Speeds look 10 knots or less. The Wave Watch continues to have a high bias on seas, albeit only about 1 foot. Buoy observations have shown seas 2 feet or less with 3 feet way offshore at 41010. Therefore will have seas 2 feet or less, except up to 3 feet well offshore (and that is probably even too generous). && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Forecasts...Lascody Impact Wx/Radar...Weitlich/Combs
Area Forecast Discussion
National Weather Service Mount Holly NJ
1126 PM EDT Fri Jul 21 2017 .SYNOPSIS... A very warm and humid air mass will remain over the area through this weekend and possibly into Monday. Meanwhile, low pressure along a roughly west to east frontal boundary will result in periods of showers and thunderstorms. By Tuesday, high pressure will build over the area bringing somewhat milder and drier conditions through through the middle of next week. A seasonally strong cold front may cross the area later in the week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Amended the forecast overnight to increase PoPs south of the Mason-Dixon Line, where an isolated storm has tracked eastward from near the Baltimore metro to Chesapeake Bay. The latest HRRR and NAM Nest (00Z) indicate that more storms may initiate through the night in advance of a weak perturbation moving through the southern Mid-Atlantic. Radar rainfall rates are fairly excessive with this storm, and given the slow storm motion and very high PWs in place downstream of the storm, some localized heavy rainfall is possible. Should more storms develop and/or the isolated storm intensify, the grids may be updated to include more enhanced wording. A light and variable wind is forecast for tonight. Low temperatures should range from the middle 60s in the elevated terrain up north to the 70s in the Philadelphia metropolitan area, southern New Jersey and on the upper Delmarva. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/... Some updated thoughts on this period... The first is that there is large spread in forecast temperatures tomorrow, likely owing to some uncertainty regarding the speed with which convection moves into the area (and downstream clouds hindering temperatures from maxing out during the afternoon). However, observations the past two days suggest that heat indices have tended to reach their maxima in the late morning (when dew points have not mixed out substantially). Though clouds may be present in the morning (in association with a perturbation moving through the southern Mid-Atlantic), I am somewhat worried the combination of temperatures and dew points will be quite uncomfortable once again in the urban corridor. My feeling is some heat product will be necessary again, particularly since this will be the third day with heat indices flirting with or exceeding the century mark. The 00Z NAM MOS numbers are quite cool (90 at KPHL), owing to more clouds. However, the GFS MOS is much warmer (95 at KPHL) with dew points likely to be higher than today. MOS has overdone temperatures the past couple days (though not by much), so although there is quite a bit of uncertainty regarding meteorological criteria being reached...the factors of it being a weekend day, the prolonged nature of the ongoing heat, and the potential for heat issues to be reached relatively early in the day all point to the need for some sort of heat-related advisory or warning. Will make the final decision with the 330 am update. The second regards severe/flood potential. There remains large uncertainty with the evolution of upstream convective clusters/complexes as they move along a quasi-zonally oriented boundary from the Ohio Valley to the southern Mid-Atlantic. High-resolution output has large variability in timing/location of the convection, but there are consistent indications of strong convection (combination of substantial instability and fast midlevel flow) and multiple rounds of storms (as upscale growth of initiating convection allows for downstream propagation along the aforementioned boundary) beginning late in the day. This leads to some concern regarding both severe storms and hydrologic issues. More details to come with the 330 am package, but some enhanced wording in the grids will probably be necessary at minimum. && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... The extended period starting Saturday night features a transition in the flow aloft from roughly zonal flow across the northern US to a somewhat more amplified pattern with troughing over the east US by the latter part of next week. In terms of weather this translates to very warm/hot and humid conditions this weekend transitioning to a milder and somewhat drier period for at least part of next week. A quasi-stationary east-west frontal boundary is expected to persist across the area through the weekend, although it may lift north a bit on Sunday. Low pressure along the front will favor low-level convergence and areas of showers and thunderstorms. PWAT values near 2 inches will support some heavy downpours and possible flooding. Also SPC has a slight risk of severe for Saturday and Sunday. Timing is tricky but there is some indication of more likely precip for Saturday night and possibly again Sunday night. By Monday morning a fairly pronounced shortwave trof is forecast to be over the Great Lakes and move east to New England by Tuesday morning. The GFS is a bit slower than the ECMWF, but either way the trof should force a cold front across the mid- Atlantic and offshore by Tuesday morning. With the frontal passage on Monday there will be a continued good chance for aftn/eve t-storms. Max temps on Monday ahead of the front look to be still a few degrees above normal. Tuesday and Wednesday should be relatively pleasant with shrtwv ridging aloft and surface high pressure moving across the area. The high is associated with a somewhat cooler and drier air mass. Looks like some low-level warm advection develops Wednesday night and the forecast carries a chance of showers at that time. Chance of precip increases on Thursday as another shrtwv trof and associated cold front approach from the NW. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... VFR conditions are forecast for much of the overnight and Saturday. Showers and strong thunderstorms are expected to approach from the west late in the day. They should begin arriving around KRDG and KABE about 2100 to 2200Z, and they are expected to reach KTTN, KPNE, KPHL and KILG around or shortly after 2300Z.This timing will be fined out as new information comes in during the overnight hours. A light and variable wind overnight becomes west to southwest on Saturday. OUTLOOK... Saturday Night through Monday...Generally VFR conditions expected, but temporarily lower cigs/vsbys in scattered showers and thunderstorms are likely at times. Tuesday and Wednesday...VFR conditions. && .MARINE... The wind is expected to favor the southwest around 10 knots tonight and it should back to the south for Saturday. Wave heights on our ocean waters will remain around 2 feet and waves on Delaware Bay should be 1 to 2 feet. Scattered showers and thunderstorms may affect the coastal waters of Delaware and far southern New Jersey, as well as Delaware Bay, tonight. OUTLOOK... Generally sub-SCA conditions are expected Saturday night through Wednesday. However winds and seas may be locally higher in scattered thunderstorms over the waters from Saturday night through Monday. RIP CURRENTS... The energy associated with the underlying 10 to 14 second southeasterly swell continues to weaken and the 6 second south southeast swell has become prominent. As a result, we will continue to carry a low risk for the development of dangerous rip currents for the balance of today and the same should be true for Saturday. && .EQUIPMENT... Dewpoint values at KDOV continue to run a few degrees over actual. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...AMC Near Term...CMS/Gaines/Iovino Short Term...CMS Long Term...AMC Aviation...AMC/Gaines/Iovino Marine...AMC/Gaines/Iovino Equipment...Staff
Area Forecast Discussion
National Weather Service Tucson AZ
110 PM MST Fri Jul 21 2017 .SYNOPSIS...Scattered to numerous afternoon and evening thunderstorms will prevail into early next week. The greatest daily thunderstorm coverage should occur east to south of Tucson with reduced thunderstorm activity across the western deserts. A less favorable pattern may temporarily bring reduced thunderstorm coverage around the middle of next week. && .DISCUSSION... Scattered showers and storms continue to fire in the higher terrain locations east of Tucson. After quite an early start to the convection, things have tempered a bit in terms of intensity. This is temporary however as much of the lower cloud cover across the area has eroded and new (more vigorous convection) is forming across the Chiricahua Mtns as well as along the Mogollon Rim. Tucson has been right on the edge of storms so far and whether that trend continues through the rest of the afternoon is the big challenge of the day. Most runs of the HRRR and latest UA WRFs suggest convection will continue to move into the area from the north. Even though most of the organized storms will be along the AZ/NM border where a remnant circulation can still be seen on satellite and where mid level lapse rates are steeper, nearly all hi-res models depict enough areal coverage that I feel comfortable hanging onto a decent mention of PoPs around town through mid evening. Boundary collisions and even the slightest bit of ascent have been all we`ve needed the past few days and not much has changed thermodynamically across the area today. Given the fact that we`re already seeing isolated storms propagating off the Catalina Mtns, I think higher than normal PoPs are still more than warranted in this case. CAPE is much more marginal as one heads west and I think most locations across western Pima Co will be dry. Similar moisture and stability indices are forecast across the region on Saturday with a bit more of an easterly component to the flow. Storms will likely form by late morning east of Tucson and attempt to descend into the deserts. They`ll be fighting a bit of a battle as additional dry air (not to mention warmer air aloft) will have moved into the western half of the state by then and how far storms make it before they dissipate is up for debate among the more reliable operational models. Looks like another decent shot at rain in Tucson, with much lower chances to the west. Confidence starts to go downhill on Sunday as the day starts off looking like a typical late morning through early evening convective event, but the past few deterministic GFS/NAM/ECMWF all indicate a weak inverted trough will move through the area late Sunday night into Monday morning. Could end up being another double shot of storms like we had a few days ago (last Saturday) with precip lingering into early Monday morning. I ended up raising PoPs a bit during this time period but confidence is always low this time of year given so many variables at play. Big picture-wise, it looks like daily storm chances will be the rule through much of next week. There is some suggestion in the guidance that low/mid level steering flow will take on a bit of a southwesterly component by the middle/end of the week which will usher in enough dry air to put the brakes on storms from Tucson westward. I agree with the idea of a slight reduction in storm chances, especially from Tucson to Ajo, although there will still be strong/moist flow across much of Sonora and I don`t see much in the way of a large scale pattern change that would prevent that from advecting into AZ. PoPs gradually return to a climo-like appearance by the end of the week but that`s certainly subject to change depending on how much convection forms over Sonora next week. && .AVIATION...Valid thru 23/00Z. VFR conditions with cloud decks generally 5k-10k ft AGL with BKN layers above, and surface wind variable in direction mainly less than 12 kts. SCT TSRA developing after 21/18Z and lingering through 22/06Z. Winds vicinity TSRA could gust 40+ kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered to numerous mainly afternoon and evening thunderstorms will continue into early next week with locally heavy rain and strong winds. Temperatures will remain below normal with a continuation of elevated humidity levels through Tuesday. Wednesday onward conditions will become a bit drier and warmer with somewhat less convection. From 20-foot winds will mainly remain below 15 mph with the exception of strong outflow winds in the vicinity of thunderstorms. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Leins/Cerniglia Visit us on Facebook...Twitter...YouTube...and at