Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/23/19

National Weather Service Albany NY
1047 PM EDT Mon Jul 22 2019 .SYNOPSIS... Periods of rain will continue overnight before tapering to scattered showers in the late morning. Drier and less humid weather returns late Tuesday afternoon and persists through the end of the work week with near seasonable temperatures. && .NEAR TERM /THROUGH TUESDAY/... As of 1047 PM EDT... A soaking rainfall continues across much of the forecast area especially from the Hudson River Valley and the eastern Catskills south and east where 1-3 inches of rainfall is much needed and may occur, as low pressure tracks across southern New England. A weak secondary impulse is moving across PA towards NJ which may allow the rain to back in from northwestward based on the latest 3-km HRRR and 12-km NAM for periods of light to moderate rain to continue towards daybreak. The system is behaving like a cool season cyclone with the mid and upper deformation zone and some embedded mesoscale banding enhancing rainfall rates across srn VT and the Berkshires. KAQW had an hourly rainfall rate of 0.56"/hr last hour. An SPS was issued for this enhancement. The PoPs and weather were retooled based on the radar and CAMs trends. Please see our PNS statement with the latest totals, where the higher amounts have been over the Capital Region, Helderbergs, Schoharie Valley, and Mohawk Valley. Lows will be in the mid 50s to lower/mid 60s. Lighter shower activity is possible well into Tuesday morning (mainly south and east of Albany) as the coastal low strengthens nearby and moves up along the coast. At the same time, drier and cooler air will be infiltrating the region from the north-northwest, bringing an end to the showers throughout the morning. High temperatures on Tuesday will be in the upper 60s to lower 70s. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... Skies will be clearing from the northwest Tuesday night as temperatures dip into 50s. Some higher locations in the Dacks could even fall into the upper 40s. Dry weather is expected Wednesday through Thursday with temperatures averaging in the mid 70s to low 80s (cooler in the higher terrain). However, the upper trough finally passes overhead on Thursday, potentially sparking an isolated shower in the Dacks. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Period will begin with troughing aloft along east coast and upper level ridge extending from southern Rockies to southeastern Canada. Ridge axis gradually shifts southeast and replaces trough over our area by later Saturday. Friday and Saturday look to have a dry northwesterly flow with fair conditions. Lows in the 50s hill towns to 60s valley areas. Highs in the upper 70s hill towns to upper 80s in the valleys. By Sunday and Monday, short waves are expected to pass to our north each day as they shear out across eastern Canada. These ridge rollers will bring a chance of showers and storms for both days, with best chances across the northern part of the forecast area. lows Sunday and Monday mainly in the 60s. Highs in the 80s to around 90. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... A wave of low pressure will move across southern New England tonight. Another low pressure system may continue the threat of showers late Tuesday morning, as it passes south of the region before improving flight conditions in the afternoon. Widespread low MVFR/IFR conditions continue across eastern NY and western New England with periods of rain, occasionally moderate to heavy especially from KALB-KPSF south and east toward KPOU. The most persistent IFR conditions especially with vsbys will be at KALB/KPSF/KPOU. KGFL is on the the northwest side of the rainshield so expect MVFR/low VFR conditions in terms of vsbys/cigs prior to 06Z. Persistent low-level moisture with the upper deformation zone of the wave after 06Z/TUE will keep low cigs/vsbys especially from KALB/KPSF south until 12Z- 14Z. Some IFR cigs and spotty LIFR are possible at KPSF and KPOU during this time frame. A gradual improvement to MVFR conditions is expected by 16Z/TUE. Some light showers may move back in from KALB/KPSF south in the late morning/early pm and we kept VCSH groups in, as the secondary wave tracks close. 18Z-22Z/TUE cigs/vsbys should be low VFR/VFR with bases 3.5-5 kft AGL with drier air filtering in the wake of the wave(s) and front. North-northeast winds 4-8 kts tonight become light. North to northwest winds at 5 to 10 kt are expected late TUE morning into the afternoon. Outlook... Tuesday Night to Saturday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... Rain will continue through tonight with isolated thunderstorms expected across far southern New York and western New England. Drier and less humid weather returns on Tuesday and persists through the end of the work week with near seasonable temperatures. By Tuesday afternoon, minimum relative humidity values will generally be between 50 and 70 percent. Light northwest winds remain in place today sustained less than 15 mph. Northwest winds increase a bit on Tuesday, sustained 15 mph in the wake of our cold front. && .HYDROLOGY... Rainfall continues this afternoon with the heaviest rainfall currently falling across southern New York into western New England. NYS Mesonet sites have recorded at least half of an inch to an inch this afternoon across many sites. Expect periods of heavy rainfall across Dutchess and Litchfield counties through the remainder of the evening before tapering to light rain showers through the overnight period. Showers remain possible through Tuesday morning as well. This heavier rainfall may lead to some flooding in poor drainage or low lying areas, but widespread flooding is not anticipated. Drier weather is expected from Tuesday afternoon through the remainder of the week. Please visit our Advanced Hydrologic Prediction Service /AHPS/ web page for specific area rivers and lakes observations and forecasts. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...JLV/Wasula NEAR TERM...JLV/Wasula SHORT TERM...JLV LONG TERM...SND AVIATION...Wasula FIRE WEATHER...JLV HYDROLOGY...JLV
Area Forecast Discussion
National Weather Service Caribou ME
1033 PM EDT Mon Jul 22 2019 .SYNOPSIS... A stationary front will remain across the Gulf of Maine this evening. A pair of low pressure waves will move along the front tonight into Tuesday. High pressure will build across the region Tuesday night into Thursday. The high will gradually move offshore Friday into Saturday. && .NEAR TERM /THROUGH TUESDAY/... 1030 PM Update... Rainfall has been light and spotty this evening as the bulk of the rain has been across southern New England. Low pres was lifting up toward the southern New England coast this evening. The latest run of the RAP matched close to the regional radar as did the 01Z HRRR. Minor tweaks were made to the precip chances to tighten things up w/precip chances dropping off as one goes n of Bangor. Llvls taking longer to moisten up with the northern areas see thin clouds allowing for a cooldown. Temps slowly cooling off with mid to upper 50s across the far n and w. Overnight night lows were tweak a degree or two downward using the latest obs to initialize. Previous Discussion... The deep southern stream moisture with PWs approaching 2 inches will be funneled along the frontal boundary near the coast. Up to an inch of rain is possible along the immediate coast tonight. There`s still some uncertainty as to the exact location between models and have taken a consensus approach based on all available models and analysis. Meanwhile, no precip is expected tonight towards northern Aroostook County and lows will dip into the upper 40s and lower 50s. Most of the precip will fall tonight for the coast, but the chance of precip and clouds will continue along the coast on Tuesday as the second wave of low pressure moves along the offshore frontal boundary. The 12Z guidance from GFS and ECMWF indicated a subtle digging of the upper trough to the west which pushes steadier precip further inland on Tuesday. Will maintain chance PoPs for Bangor and much of the Downeast region for now and let the night crew take a look at 00Z analysis and guidance. Highs will only be in the upper best...tomorrow. The warmest temps on Tuesday will be in the far NW portion of the forecast area where some mid to upper 70s are possible. The upper trough may generate some light, low-topped showers inland, but most of the energy will be focused along the frontal boundary offshore. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... Fairly quiet weather Tuesday night through Thursday with surface high pressure over the region. A weak upper level trough on Wednesday will bring a slight chance of afternoon showers, then another weak trough on Thursday could ignite a few afternoon showers as well. Little or no chance of storms, though, as air is too dry and CAPEs too low. Generally partly cloudy skies Tuesday night through Thursday with more clouds in the afternoon hours than overnight or morning hours due to diurnal convection. Temperatures near or a touch below average. Light winds through the period. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Thursday night through the weekend, an upper level high builds over the region with a surface high over the Gulf of Maine. This will lead to warmer southwest flow. Highs will be in the 80s and it will be fairly muggy. The upper high over the region inches just east of us late Sunday and Monday, allowing for a return of mainly afternoon thunderstorm chances. Models are in fairly good agreement and forecast confidence is higher than usual. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... NEAR TERM: From HUL/MLT/GNR northward, VFR conditions with light winds are forecast. BGR and BHB will have cig/vis reductions to IFR in rain tonight into Tuesday morning. These sites will improve to MVFR after mid morning Tuesday. BHB is most likely to experience IFR conditions tonight. SHORT TERM: Tue night through Sat...Mainly VFR with light winds except for afternoon sea breezes mainly Thursday through Saturday. && .MARINE... NEAR TERM: Light winds and seas under 2 feet are expected. Patchy fog and rain are the primary concerns. The rain could be heavy at times. SHORT TERM: Conditions remaining below small craft levels. Marine fog possible toward Thursday night and Friday as onshore flow develops. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service Quad Cities IA IL
626 PM CDT Mon Jul 22 2019 ...AVIATION UPDATE... .UPDATE... Issued at 420 PM CDT Mon Jul 22 2019 Isolated to scattered showers have developed in the far south during peak heating. Forecast has been updated to reflect this and any showers should dissipate by 7 PM as the atmosphere begins to cool. && .SYNOPSIS... Issued at 310 PM CDT Mon Jul 22 2019 High pressure centered in the northern Plains bringing a delightful day to the dvn cwa. Other than sct high-based cu there was plenty of sunshine along with temperatures in the mid 70s to around 80 and comfortable humidity. && .SHORT TERM...(This Evening through Tuesday) ISSUED AT 310 PM CDT Mon Jul 22 2019 Tonight: High pressure bringing very comfortable weather in the short term. With clear skies, a dry airmass and light winds good radiational cooling should drop temperatures into the upper 50s at most locations. These readings are similar to what was observed in central/southern MN last night. Tuesday: High pressure in control so plenty of sunshine with afternoon temperatures rising into the lower 80s, but dewpoints will be comfortable in the upper 50s. .LONG TERM...(Tuesday Night through Monday) ISSUED AT 310 PM CDT Mon Jul 22 2019 A mainly dry and warm period but nothing extreme. Tuesday night: An upper level disturbance riding southeast in the eastern trough may trigger isolated showers or storms in northern IL in the evening hours. The NAMNEST suggests this but the HRRR keeps it in northeast IL. Confidence is low having any storms as far west as the dvn cwa so will keep it dry for now and let later shifts monitor the model trends. Wednesday through Friday: Dry and warm with near normal temperatures with the area under a northwest flow and sprawling high pressure at the surface. Highs will be in the 80s with lows in the 60s. Saturday through Monday: Flow becomes more zonal allowing the heat and humidity to return, but nothing like the heat wave we recently had. (h8 temperatures are progged at +20c instead of the +27 during the heat wave). Temperatures look to push to around 90 with lows in the 60s. GFS/ECMWF similar in bringing a cold front into the area next Monday with the potential for thunderstorms. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) ISSUED AT 625 PM CDT Mon Jul 22 2019 VFR conditions will be seen through 00z/24 as high pressure moves through the Midwest. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ UPDATE...08 SYNOPSIS...Haase SHORT TERM...Haase LONG TERM...Haase AVIATION...08
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
330 PM MDT Mon Jul 22 2019 .SYNOPSIS... A cooler but more humid airmass has settled across the region. Showers and thunderstorms over the Gila Region, Sacramento, and San Andres Mountain will slowly drift south and southwest into the lower elevations this evening, with isolated to scattered thunderstorms expected to continue through the early evening hours. Some highly localized heavy downpours are expected, with possible spot flooding. Coverage will be spotty, and likely will favor areas west of the Rio Grande. More widespread showers with embedded thunderstorms are expected again later tonight and possibly lingering into Tuesday morning, with another round of afternoon thunderstorms Tuesday expected to mainly favor southwestern New Mexico Tuesday evening. We`ll catch a break on Wednesday as drier air aloft moves in. While a classic monsoon pattern has yet to be established, additional moisture coming into the region from the north will bring a slight increase in thunderstorms Thursday and into the weekend. && .DISCUSSION... Plenty of moisture is in place across the area, with PW values remaining around 1.20 to 1.40 inches. The main problem so far today is with the lack of instability due to widespread convective debris/cloud cover. But the cloud cover has been slowly eroding across most of the area, allowing for pockets of stronger surface heating to develop. As of 3 PM, most lowland areas were within a degree or two either side of 90, which is roughly around the convective temp per RAP soundings. However, instability remains weak, particularly along the Rio Grande Valley, and we remain significantly capped aloft, especially in far SW New Mexico and also parts of far West Texas. Thunderstorms have developed near the western rim of the Sacramento Mountains, as well as over the much of the higher elevations in the Gila Region. Steering flow is from the NE or ENE over most of the area, which by itself is ideal for propagating storms off the Sacramento Mountains and into the lower Tularosa Basin and El Paso/Las Cruces areas. However, with the lack of instability, we are unlikely to initiate widespread convection unless we can get a little more surface heating. NAM/GFS both indicate a shortwave trough/vortmax embedded in the NE flow over east-central New Mexico, likely the models` representation of an MCV which is evident in visible satellite imagery. Additional thunderstorm development is possible ahead of this feature assuming the circulation/vort max aloft can become displaced from the cooler/stable air beneath it. CAMs models are struggling with the situation, as is often the case when there is a lot of convective debris and cloud cover about. Most are over-doing the coverage of ongoing convection, but there is a general theme of continuing to develop convection over the Sacramentos over the next few hours, with activity propagating into the lowlands, but sliding off just to the west of the El Paso area, presumably due to the stable air located over most of El Paso County east of the Franklins (we`ve warmed up to 90 at Santa Teresa, while KELP is still lagging behind at 86). Storms over the Gila look to propogate more to the WSW, grazing northern Hidalgo County. All of this is to say while widely scattered storms with heavy rainfall are still expected before sunset, coverage in most of the lowlands looks to be spotty, and El Paso could easily be missed. Tonight is a different story, with most models suggesting widespread showers and isolated thunderstorms redeveloping later tonight, the result of outflow boundary interactions, some improved dynamics for lift aloft, and weak/moderate instability. Overnight convection is likely to once again influence rain chances tomorrow due to left over cloud cover and rain-cooled air. Overall, the better chances for additional thunderstorms in the afternoon look to be west of the Rio Grande, and in the higher terrain of the Sacramento Mountains, as drier air aloft looks to begin filtering into eastern areas. The dry air aloft will result in a widespread down-tick in thunderstorms on Wednesday, though isolated thunderstorms will remain possible over the higher terrain areas. Thursday and into the weekend, additional moisture looks to rotate around the ridge in drop into the region from the north (taking the long way around), with shower and thunderstorm chances increasing again. However, it`s still not a classic, robust monsoon pattern, and weak instability looks to continue to inhibit thunderstorm coverage in the lowlands. && .AVIATION...Valid 23/00Z-24/00Z.. VFR conds currently of SCT/BKN100 BKN250. Conds will gradually lower as convection develops to...BKN080CB BKN/OVC200 scattered -TSRA isolated OVC030CB +TSRA vsby 1-3SM, mostly over mountains and west of the Cont Divide. Wind gusts of 25-35 kts also possible with some of these storms. && .FIRE WEATHER... A cool front has pushed in from the east, bringing moisture and somewhat cooler temperatures to the fire zones. Scattered to numerous thunderstorms should develop late this afternoon and tonight. Some storms could produce heavy rainfall and flash flooding. Upper high will drop down over western New Mexico Wednesday and Thursday, with drier air and thunderstorms decreasing to mainly isolated over mountains. Upper high then drifts west to SW Arizona for the weekend, once again allowing more moisture and an increase in the chance of thunderstorms. No significant non- thunderstorm winds expected through the week. Temperatures will be much cooler than recently with high temperatures at or below normal for the week. Min RHs in the 30s lowlands on Tuesday decreasing to 15-20% Wednesday through Friday. Min RHs 50-60% mountains on Tuesday decreasing to 25-35% Wednesday through Friday. && .PRELIMINARY POINT TEMPS/POPS... El Paso 72 88 71 93 / 40 50 10 0 Sierra Blanca 66 82 64 87 / 40 50 10 0 Las Cruces 70 86 68 91 / 40 50 20 0 Alamogordo 69 86 66 91 / 50 50 20 10 Cloudcroft 51 64 50 69 / 70 60 20 20 Truth or Consequences 68 85 69 90 / 50 50 30 10 Silver City 63 80 63 84 / 60 60 40 20 Deming 70 87 67 91 / 50 50 30 10 Lordsburg 71 88 69 92 / 60 40 30 10 West El Paso Metro 73 88 72 93 / 40 50 10 0 Dell City 69 87 67 92 / 50 50 10 0 Fort Hancock 72 90 70 95 / 40 50 10 0 Loma Linda 66 82 67 87 / 40 50 10 0 Fabens 72 88 71 93 / 40 50 10 0 Santa Teresa 71 88 69 91 / 40 50 10 0 White Sands HQ 71 87 70 91 / 50 50 10 0 Jornada Range 69 87 67 91 / 50 50 20 0 Hatch 69 88 68 92 / 50 50 20 0 Columbus 71 89 70 93 / 40 40 20 0 Orogrande 70 86 68 91 / 40 50 10 0 Mayhill 56 73 54 79 / 70 60 20 20 Mescalero 56 74 53 78 / 70 60 20 20 Timberon 56 71 52 76 / 60 60 20 10 Winston 58 78 58 84 / 60 60 40 30 Hillsboro 64 84 64 89 / 60 60 40 20 Spaceport 66 86 66 90 / 50 50 20 0 Lake Roberts 58 80 56 85 / 60 60 40 30 Hurley 64 82 63 86 / 60 50 40 20 Cliff 62 88 61 92 / 60 60 40 20 Mule Creek 65 85 66 88 / 60 60 40 30 Faywood 66 82 65 86 / 50 60 40 10 Animas 71 91 69 94 / 50 30 30 10 Hachita 69 88 67 92 / 40 30 30 10 Antelope Wells 70 89 68 92 / 40 40 30 10 Cloverdale 68 86 66 88 / 50 40 30 10 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 25-Hardiman / 14-Hefner
Area Forecast Discussion
National Weather Service Hastings NE
621 PM CDT Mon Jul 22 2019 .SHORT TERM...(This evening through Tuesday) Issued at 255 PM CDT Mon Jul 22 2019 Aloft: WV imagery...aircraft winds...and RAP tropopause analyses showed moderately-amplified NW flow over NEB/KS. A ridge was over the Rckys...anchored by a subtropical high over NM...and a trof was over the GtLks/Midwest. These features will not change thru tomorrow other than the trof deepening over the Ern USA. Surface: 1026 mb high pres was over the Dakotas. This high will drift S into cntrl NEB tonight and then drift to OMA by 00Z/Wed. A refreshingly cool/comfortable air mass has settled into the rgn. High temps will be about 10F below normal this afternoon. Tonight: CU will rapidly dissipate early eve leaving clr skies. Patchy fog should dvlp toward dawn...primarily ovr S-cntrl NEB. Mdls are not in great agreement on occurrence or coverage...which is usually suggestive of patchy nature. The air mass is relatively dry...but with high pres settling overhead...temps should have no problem radiating past the cross-over temp (lowest dwpt that occurs near the time of the afternoon high). This should result in VSBYs of 3-5 mi...but where temps drop svrl degs below the cross- over temp (N and W of the Tri-Cities)...some locally dense fog (1/4 mi or less) could occur. Used a blend of MOS for lows. Would not be surprised to see temps drop into the upr 40s in the valleys acrs Valley/Greeley counties. Tue: Any fog will dissipate early-mid AM depending on how bad it gets. The thinner/shallower...the quicker it will dissipate. After that...sunny and beautiful with a few CU forming with daytime heating. Temps nearly 10F below normal again. Comfortable with dwpts in the 50s. .LONG TERM...(Tuesday night through Monday) Issued at 255 PM CDT Mon Jul 22 2019 Aloft: The longwave flow will deamplify and basically become zonal by next wknd. A strong shrtwv trof is fcst to move in from the Pac and head E along the US-Can border. This will suppress the subtropical high force it to migrate to near LAS. The flow will generally remain from the NW over NEB/KS. The exception will be Sat night when a shrtwv trof is fcst to move thru. The last 2 runs of the EC/GFS-FV3/UKMET/CMC are in good agreement on this scenario...and agree with the 12Z EC ensemble mean. Surface: Return flow will strengthen Wed as high pres conts to slowly creep E to near CHI. That high will cont E into PA Thu. Meanwhile...low pres will be moving thru cntrl Canada and its associated cool front will weaken into a trof as it enters Wrn NEB. Another cool front associated with this low will drop into the Nrn Plns Fri but is fcst to stall along the NEB-SD border thru Sat. It`s possible this front could sag deeper into NEB Sun- Mon...but overall the CWA should remain on the warm side of the front. Even if the front does slip into the won`t affect temps much. Temps: Contd below normal Wed-Thu...then back to normal Fri-Mon. Rain/Tstms: No significant precip expected. There could be a spotty tstm or two...but the next few days are looking predominantly dry. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday) Issued at 620 PM CDT Mon Jul 22 2019 VFR conditions should prevail through the period although there is a small chance for some MVFR conditions towards morning with some patchy fog possible. For the time being...kept VSBYs at 6 SM and will need to modify if fog becomes more of an issue towards morning. Otherwise...winds will be light and variable through most of the period as an area of surface high pressure slides across the local area and settles into the Missouri River valley by Tuesday afternoon. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ SHORT TERM...Kelley LONG TERM...Kelley AVIATION...Rossi
Area Forecast Discussion
National Weather Service Houston/Galveston TX
700 PM CDT Mon Jul 22 2019 .SHORT TERM [Tuesday Through Wednesday Night]... Storms along the outflow boundary pushing southward and have increased rain chances over the north this evening and will speed up the windshift to account for this faster timing. Increased cloud cover overnight as well. 45 && .AVIATION [00Z TAF Issuance]... Accelerated the wind shift and increased the coverage of storms over the CLL/UTS areas this evening and then into the Houston metro terminals primary impacts with VCSH/VCTS/TEMPO for storms should be 9-13z...latest HRRR indicating the precip departs an drier conditions quickly set in along with north-northeast winds. Could get a little gusty over the southern terminals especially near LBX/GLS after 15z. 45 && .TROPICAL... Against the odds we now have a sheared up Tropical Depression 3 east of Miami. It should continue to move north and northeast in the coming 24 hours. 45 && .PREV DISCUSSION /Issued 402 PM CDT Mon Jul 22 2019/... .LONG TERM... A very pleasant temperature forecast that is a few months early... interior dew points falling into the upper 50s (north) to middle 60s (coastal) will make it feel like October in July! Mornings is when this unseasonable air mass will be most felt as minimum temperature readings fall into the lower to middle 60s (rural) to around 70 in more urbanized areas. Mid week afternoons will warm into the bearable upper 80s to lower 90s. Rain will enter the forecast over the weekend and into early next week. With the region still falling in a general height weakness between two large highs planted over the 4 Corners region and the eastern Atlantic...higher moisture will pick up %RHs and rain chances to low end probabilities by Sunday and Monday afternoons. Winds come back around to onshore by Friday and the moisture pump commences a return to a normal summer-like pattern for us here in southeastern Texas. So, scattered -TSRA will be in play along with the late July heat and mugginess. 31 .MARINE... Weak high pressure over the western Gulf of Mexico will maintain a SW-S wind over the coastal waters tonight. The pressure gradient is not particularly tight so wind speeds not expected to exceed 15 knots through Monday night unless influenced by convection. A rare July cold front is expected to cross the coastal waters Tuesday morning and winds will become N in the wake of the front by Tuesday evening and veer to the NE overnight into Wednesday. A short lived SCEC may be required for parts of the Gulf waters Tues Night/early Wednesday. A moderate NE flow is expected Wed/Thu as high pressure builds toward the mid Mississippi river valley. The Tuesday cold front will return north as a weak warm front on Thursday night. East winds Thursday night will become SE as the front pushes north with onshore winds then persisting through next weekend. No rip current or tide issues are expected through Monday night. 43 && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 76 90 66 91 65 / 60 10 10 0 0 Houston (IAH) 76 90 70 91 68 / 50 20 10 0 0 Galveston (GLS) 82 90 77 88 77 / 50 50 40 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...None. GM...None. && $$ SHORT TERM...45 LONG TERM...11 AVIATION...45
Area Forecast Discussion
National Weather Service Marquette MI
744 PM EDT Mon Jul 22 2019 .SHORT TERM...(This evening through Tuesday) Issued at 341 PM EDT MON JUL 22 2019 WV imagery and RAP analysis indicated a mid/upper level ridge from the northern Rockies into Saskatchewan and a low over northwest Quebec resulting in a cyclonic nw flow through the northern Great Lakes. A shortwave trough dropping sse through nw Ontario supported a cluster of showers and t-storms. Otherwise, high pressure building from the northern Plains into the western Great Lakes continued to bring dry cool air into the region on anticyclonic northerly low level flow. Steep sfc-850 mb lapse rates supporting some cu over mainly the central and eastern U.P. this afternoon. High temps thus far have generally ranged from the upper 60s to lower 70s near the lake to the upper 70s south. Dew points lowering through the 40s have also dropped RHs into the low 30 pct range elevating wildfire concerns with nw winds gusting near 20 mph. Tonight, the Ontario shortwave will slide through Lake Superior and Upper Michigan bringing the potential for some isolated showers or sprinkles. Given current trends, some thunder may be possible into western Lake Superior and possibly western Upper Michigan. However, the weak forcing and limited MUCAPE will be marginal to support to thunder. Tuesday, with the shortwave still moving through in the morning into early afternoon, some of fcst soundings (particularly the NAM) have some instability developing over the southeast and south central portions of the CWA. With 100-200 j/kg CAPE fcst, will mention slight chc for a thunderstorm over these areas. A few of the models indicate a more subtle shortwave moving down from Ontario again in the afternoon, but given rising heights fcst into nw Ontario and western Lake Superior wl keep fcst generally dry across the rest of the cwa. Expect similar high temps as today with values from the upper 60s to lower 70s near Lake Superior to mid to upper 70s well inland. Lowering RHs in the afternoon to around 35 pct over inland areas and nw winds gusting near 20 mph could perhaps lead to elevated wildfire concerns. .LONG TERM...(Tuesday night through Monday) Issued at 243 PM EDT MON JUL 22 2019 An amplified but relatively stagnant pattern over the CONUS will be in place for the middle of this week, with upper ridging over the west and a trough just to our east. As a result, broad surface high pressure will be stretched north to south across the entire Plains region from southern Manitoba into Texas and eastward to the western Great Lakes to start the long term period Tuesday evening. Dry conditions will prevail much of this week as this high slowly traverses the CONUS, with the next weather system expected to impact the region Friday into Saturday. Tuesday night into Wednesday should be partly cloudy, quiet and seasonal, with daytime temperatures perhaps a couple degrees above normal maxing out in the low to mid 80s inland. Upper level flow will remain northwesterly Wednesday and much of Thursday as well. The surface high will begin to head east to the Ohio Valley by Thursday afternoon as a closed low begins to push through Saskatchewan. While low level flow over Upper Michigan will turn to the southwest and dew points will begin to rise a little, there won`t be much opportunity for strong moisture transport right away. With relatively dry air remaining in place aloft as well, concerns on Thursday will focus on the potential for elevated fire weather conditions. At this time, the forecast only calls for minRH values Thursday afternoon in the mid to upper 30s. But forecast soundings continue to indicate ample dry air above 5kft that may mix down enough to bring RH values a tad lower in some locations. A little breeziness is expected as well with afternoon wind gusts of 15-20 mph. Thus, after about 5 days with no rain across the area, marginal chances for elevated fire weather conditions are expected. Some relief from the dryness will come late Thursday night into Friday as the approaching closed low opens up and the gradually weakening trough digs across Lake Superior. Despite the antecedent dry air, model consensus indicates the potential for 1.5+" pwat values as the trough nears, or approximately 90th percentile for late July. Models are also in good agreement in terms of arrival timing with precipitation chances increasing over the west just before sunrise Friday and sticking around through the day. At this time, severe storms appear somewhat unlikely but GEFS plumes indicate high uncertainty in available CAPE during this time period so this will require monitoring. It`s also worth noting that gusty winds are possible Friday as the pressure gradient tightens with a high remaining in place over the OH Valley/Mid-Atlantic region. A few showers/storms may then linger over the east as late as Saturday morning before a weak shortwave ridge dries things out Saturday night. A second trough will likely approach sometime in the Sunday afternoon to Monday morning time frame but forecast uncertainty increases that far out. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 740 PM EDT MON JUL 22 2019 As a disturbance crosses the region tonight, some sprinkles/light rain showers may be possible in the KIWD and KCMX terminal areas, with chances diminishing by the time it reaches KSAW. Category reductions are not expected through this TAF period at any of the terminals, yielding predominantly VFR conditions. W-NW winds will prevail through early tomorrow, becoming more northerly as the day progresses. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 341 PM EDT MON JUL 22 2019 Winds below 20 knots are expected through much of the week under prevailing high pressure. The approach of a sfc trough late in the week (Thu night into Fri) will result in an increase of southwest winds to perhaps 25 knots at that time. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Voss LONG TERM...KCW AVIATION...lg MARINE...Voss
Area Forecast Discussion
National Weather Service Pueblo CO
751 PM MDT Mon Jul 22 2019 .UPDATE... Issued at 748 PM MDT Mon Jul 22 2019 Adjusted POPs based on current radar obs. Flash flooding has occurred over the Junkins and Spring burn scars. Appears life threatening conditions are occurring, especially over the Spring burn scar. /Hodanish && .SHORT TERM...(This evening through Tuesday) Issued at 257 PM MDT Mon Jul 22 2019 Storms this afternoon have been mainly focused over the mtns along the Continental Divide, with a few also over the Sangre de Cristo Mtns. The HRRR and NAM continue to show the focus for thunderstorms mainly staying over the mountains and high valleys this evening. However, they do have a few storms making their way out over the I- 25 corridor. The HRRR and NAM Nest shows the potential for heavy rain over the Hayden Pass and Spring burn scars this evening, so will have to monitor this possibility. By midnight, most or all of the convection is expected to end. There could be a few strong storms as well this evening, with hail and strong wind gusts. On Tue, the upper ridge center will be over eastern UT and far western CO. There will still be plenty of moisture over the area, and similar to today, the mtns and high valleys should see the most showers and thunderstorm activity. With the I-25 corridor and eastern plains probably not seeing any activity through at least midafternoon. By late afternoon a couple storms may try to move off the mtns and into the I-25 corridor, especially over El Paso County. Temps acrs the southeast plains on Tue are expected to be a little warmer, with highs in the 80s, with maybe some lower 90s, while the high valleys should mostly be in the lower 80s. .LONG TERM...(Tuesday night through Monday) Issued at 257 PM MDT Mon Jul 22 2019 .Tuesday night into Wednesday...Upper high over the Four Corners region begins to move southward. Flow aloft becomes more westerly on Wednesday with a shortwave moving across the northern Rockies. Precipitable waters decrease over the plains as surface high moves to the east and a weak lee trough develops. Still enough moisture for diurnal thunderstorms to develop over the mountains. Flow aloft remains northerly and thunderstorms will be less likely to move off of the mountains. Like the NBM grids with the higher PoPs and modest QPF as expect thunderstorms to be fairly widespread but with light QPF. Temperatures continue to increase over the plains to be near average. .Thursday...As the trough moves to the east into the northern High Plains, a weak cold front can may into the eastern plains. Weak upslope behind the front will increase low level moisture. Higher QPF along the eastern mountains in the NBM hints add the more abundant low level moisture along with an increase in moisture aloft. Temperatures remain near seasonal values. .Friday through Monday...Upper high drifts southward to be centered over Arizona. Flow aloft becomes more westerly with drier air aloft gradually moving into the region. Still enough moisture for diurnal convection to develop over the mountains. With westerly flow aloft, convection has a better chance of moving off of the mountains. Will have to watch for another weak cold front passage over the plains as the upper trough moves into the northern High Plains over the weekend. Upslope behind a cold front could bring increased moisture to the plains. -PGW-- && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) Issued at 257 PM MDT Mon Jul 22 2019 KCOS could see some showers/tstms in the vicinity early this evening, otherwise VFR conditions are expected thru the next 24 hrs. KPUB could see some showers/tstms move close to the vicinity between about 02Z and 05Z, but chances look fairly low at this time. Otherwise, KPUB should see VFR conditions the next 24 hrs. KALS cloud see some showers/tstms in the vicininty through about 04Z this evening, and then again late Tue afternoon, otherwise VFR conditions are expected. && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...HODANISH SHORT TERM...28 LONG TERM...PGW AVIATION...28
National Weather Service Raleigh NC
800 PM EDT Mon Jul 22 2019 .SYNOPSIS... A cold front will move across North Carolina late tonight and Tuesday, stalling near the coast Tuesday night into Wednesday. Clouds and numerous showers and thunderstorms will bring cooling relief. High pressure will bring drier and cooler air mid to late week. && .NEAR TERM /THROUGH TONIGHT/... As of 800 PM Monday... Heat Advisory has ended... Severe threat diminishing this evening... Isolated thunderstorms over the Sandhills and Central Coastal Plain worked on DCAPE values of 1300 to 1400 J/KG to bring 50-60 mph wind gusts to a few spots early this evening. The DCAPE values were lowering in the east with developing CINH, diminishing the severe threat. The larger and more clustered thunderstorms were over the NW Piedmont, moving NE toward the northern Piedmont and southern VA. However, this region has been the most stable late today as cirrus/cirrostratus blow off from the storms over western NC have been drifting southeast over this region, with somewhat limited heating. Even though the focus for convection should continue to be over the west and north Piedmont into the Northern Coastal Plain, mainly along and north of the Triad to the Triangle to Rocky Mount. This region still had 1000 to 2000+ MLCAPES of down east. The cool pool over the NW part of NC appears that it will possibly enhance some convection over areas from potentially Charlotte to Raleigh as the boundary produced by the cool pool and outflows may become more active. We will have higher POP north, with low POP SE (where the sea breeze boundary has penetrated NW to near KFAY and north of Clinton - stabilizing them. Additional MCV`s moving east across TN/KY along with the cold front drifting southeast into WVA will approach from the west and north later tonight. This may continue the higher or likely POP there overnight. Lows in the 70s in the pre-frontal environment. && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... As of 350 PM Monday... Convection may be ongoing across portions of the nrn and nwrn NC Piedmont and adjacent srn and swrn VA at the start of the period, fueled by a continued swly 850 mb/LLJ along and atop outflow from overnight convection, and influenced by the MCV now over wrn KY. Meanwhile, the synoptic front will stretch at 12Z Tue from the nrn middle Atlantic coast swwd across cntl VA, nwrn/wrn NC, and the TN Valley. The front will move sewd and either merge with the preceding outflow, or convection will redevelop and strengthen along the outflow, with subsequent linear convective evolution and effective cold front development immediately preceding the synoptic front. In either case, the timing is delayed relative to previous model guidance; and this should provide for a larger and hotter warm sector and pre-convective environment across all but the nrn and nwrn NC Piedmont. Effective bulk shear is expected to increase into the 30-40 kt range, as the positive tilt trough aloft and preceding 20-30 meter mid lvl height falls, and right entrance region of the related swly upr jet streak, move east of the Appalachians. A linear storm mode is anticipated given the orientation of shear vectors generally parallel to the front/outflow, supportive of a primary risk of damaging wind gusts that may locally exceed 60 mph in bowing/LEWP segments. Additionally, a couple of embedded, short-lived supercells and risk of an isolated tornado will also be possible, as the mesocyclones track within a locally-enhanced zone of otherwise marginal SRH along and immediately behind the convective line. Indeed, recent runs of the HRRR and NAMNest depict at least a few relatively/unseasonably long UH tracks across cntl NC and sern VA on Tue. In addition to the severe threat, locally heavy rain and risk of flooding will be possible as the convection and trailing stratiform rain move ewd, amidst and coincident with an axis of precipitable water values around two inches. So while basin average amounts of one half to one to one and a half inches are expected, highest over the ne Piedmont and Coastal Plain, locally two to three inches will be possible. Given the longer warm sector duration, temperatures have been raised, to upr 80s-lwr 90s over the Sandhills and srn and cntl Coastal Plain, ranging to upr 70s over the nrn and nwrn Piedmont. Although the deep convection will have moved east of the RAH cwfa by Tue evening, lingering stratiform rain and cloudiness will likely persist into Tue night, with drier and cooler air gradually filtering in below and supporting lows in the 60s. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... As of 245 PM Monday... Wed will start the first multi-day stretch of below-normal temperatures that most of us have seen since the third week of June. The cold front will have pushed well SE of central NC by Wed morning, as a large Canadian-source surface high builds in from the WNW. The mid level trough axis will move in from the NW Wed before stalling out through central NC and becoming increasingly weak and baggy Thu, as the northern portion of the trough lifts quickly NE over the NW Atlantic. We may continue to see high cloudiness over our SE sections, E of the dying shear axis, Wed/Thu, but otherwise the low PW and stable mid levels will ensure lots of sunshine and dry weather. The surface high`s center will drift over the Mid Atlantic region Thu night before moving NE and away from NC on Fri, instigating the onset of some air mass modification, although the ridge will continue to extend SW through our area through the weekend, keeping dewpoints low. This surface ridge will weaken further Sun/Mon, while the dissipating mid level shear axis pushes just offshore and finally loses definition as heights aloft rise over the Southeast. This should prompt temps to inch back closer to normal by Sun and just above normal Mon. With a persistent dry and stable column and no apparent trigger for convection, will maintain a dry forecast through at least Mon. -GIH && .AVIATION /18Z MONDAY THROUGH FRIDAY/... As of 805 PM Monday... VFR conditions are expected this afternoon, with breezy swly surface winds that will diminish after sunset. The exception to VFR will be scattered showers and storms with MVFR CIGS and lower VSBYS, mainly north and west including KGSO and KINT to KRWI. Showers and isolated storms may be ongoing over the Piedmont Tue morning, along the aforementioned outflow boundary, with subsequent development of a line of storms and trailing rain that will spread sewd across cntl NC on Tue, including at INT/GSO just before 18Z, and elsewhere between 18Z-00Z. Outlook: After lingering rain and sub-VFR ceilings at RWI and FAY Tue night, high pressure will build across the middle Atlantic states and provide for mainly dry, VFR conditions through the rest of the week. && .CLIMATE... Record high temperatures and years for today. RDU GSO FAY Mon 7/22 103/2011 101/1926 107/1932 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...Badgett/MWS SHORT TERM...MWS LONG TERM...Hartfield AVIATION...MWS/PWB CLIMATE...CC
Area Forecast Discussion
National Weather Service San Diego CA
607 PM PDT Mon Jul 22 2019 .QUICK UPDATE... Sent a quick update to the forecast to account for the extensive high cloud shield across the region due to blowoff from earlier convection. No other changes at this time. && .SYNOPSIS... High pressure aloft will expand over the Southwest early this week, bringing warm days and less extensive night and morning coastal low clouds. Increasing moisture from the southeast will mean more high cloudiness and an increasing chance of showers and thunderstorms, mainly in the afternoons and early evenings and mainly over the mountains and deserts. The best chances of strong thunderstorms with locally heavy rain is Tuesday through Thursday. Dry weather will likely return by next weekend. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... Some thunderstorms had formed over the region as of early afternoon as the decrease in mid-high clouds have allowed for better surface heating. A few lightning strikes in quick-moving weak convective cells occurred earlier, including a couple near Palm Springs a little before 10 AM. Scattered thunderstorms will occur mainly over the mountains this afternoon, but given the southeast flow, a few cells could drift into the valleys. Durations will generally be short as, evidenced by the northern Baja convection, the thunderstorms modify the environment by the cooling. HRRR and HREF show relatively limited amounts of precip, so total amounts should generally be under 1/2 inch this afternoon. The upper high is now over the 4 Corners and will stay in that area through about Thursday and bring us moist southeast flow aloft. Winds in the mid levels will decrease by about half, which will help the taller pulse-type thunderstorms to better form, though near saturation at times in the 500-300 MB layers may produce enough clouds at times to inhibit the convection. Some of the higher level moisture will be dependent on convection upstream, such as over Sonora, the day before. Where thunderstorms form, there could be brief heavy rain, with a possibility of isolated flash flooding, though HREF solutions show a very low chance of greater than one inch of precipitation anywhere Tuesday, at least for now. Thunderstorms will mostly be over the mountains and deserts, but some convergence along the Elsinore Convergence Zone in the Inland Empire could produce a few thunderstorms there Tuesday or Wednesday afternoon, especially with surface temperatures around 100 degrees providing some instability. The moisture decreases some Thursday, though the height level of the moisture, more around 700 MB, less above, may be more favorable for thunderstorms partly due to fewer high clouds. GEFS is consistent with its ensemble solutions with the placement of the upper high over the 4 Corners through Friday, then the solutions gradually divergence over the weekend with more than half the solutions having the upper high shift south which would place us under drier southwest flow, mostly due to troughing in the northern part of the West, but other solutions only have a slight shift southwest, which could maintain isolated thunderstorms. For now, will lean towards the drier solution but keep our eyes open. Temperatures will be a little above normal this week, except near or just slightly below normal in the deserts due to the moisture, though the humidity will make it feel warmer there. With the drying late in the week, temperatures in the deserts could rebound above 110 degrees again. && .AVIATION... 221945Z...Coast/Valleys...FEW-SCT low clouds with bases around 1000 ft MSL and tops to 1600 ft MSL this afternoon. Low clouds will be less in coverage tonight, but could impact KSAN, KCRQ and KSNA with cigs 800-1000 ft MSL at times between 08Z and 16Z Tuesday. Mountains/Deserts...SCT-BKN clouds AOA 10000 ft MSL early this afternoon. FEW-SCT TSRA over the mountains this afternoon/evening. Lightning VCNTY KPSP, KTRM, KSBD and KONT is possible but low probability. && .MARINE... No hazardous marine weather expected through Friday. && .SKYWARN... There is a small chance that Skywarn activation will be needed later today. Skywarn could be activated any afternoon and early evening through Friday due to thunderstorm activity. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...NONE. PZ...NONE. && $$ PUBLIC...Maxwell/JMB AVIATION/MARINE...PG
Area Forecast Discussion...UPDATED
National Weather Service Shreveport LA
955 PM CDT Mon Jul 22 2019 .UPDATE... A cold front was located from near Jacksonville TX, to near Shreveport, to just north of Bastrop, LA. An initial line of scattered convection and an associated outflow boundary has nearly exited the CWA to the south. Most of this activity has been gradually diminishing in intensity and coverage due to the loss of diurnal instability and as a shortwave trough axis moves southeast of the area. Additional showers have been developing in the post-frontal environment over Southern Arkansas. Some of the model guidance has suggests re-development may occur along the front as another shortwave trough axis dives southward across Missouri and Arkansas towards the Tennessee River Valley during the overnight hours. Many of the models have been too slow and overly aggressive with the QPF with this front. The HRRR appears to have a better handle on the forecast, and the 00z NAM generally shows a similar forecast as the HRRR. PoPs were trimmed to match the latest radar trends, and slight chance to low-end chance PoPs were maintained after midnight tonight based on the above thinking. No other major edits were needed. Updated text products will be sent shortly. CN && .PREV DISCUSSION... /issued 709 PM CDT Mon Jul 22 2019/ AVIATION... For the 23/00z TAFs, a line of scattered to broken convection continues to move southeast across the area ahead of an advancing cold front. KLFK and KMLU will still be affected by this leading band of showers and storms for the first few hours of the TAF period. Additional widely scattered showers have been developing in Southern Arkansas in the post-frontal environment. Some of this activity could also affect KTXK, KELD, and KSHV before gradually dissipating by 23/06z. MVFR ceilings are expected to develop during the overnight hours, but the clouds should gradually lift and scatter during the daytime Tuesday. Surface winds will shift to the north and northeast at all sites behind the front. Wind speeds will increase to 10 to 15 kts with gusts near 20 kts at most terminals after 23/15z. CN PREV DISCUSSION... /issued 250 PM CDT Mon Jul 22 2019/ SHORT TERM.../Tonight through Tuesday Night/ An unseasonal cold front wrapping around across Red River Valley into ne TX with a prefrontal band of developing tstms moving sewd across ne TX. Further east, this shallow airmass has stalled frontal boundary near the Arkansas River Valley where some mid 70`s dewpoints still reside. While ne TX/se OK begin to see some clearing with perhaps only isold redevelopment with the actual front, moisture will continue to pool in sw AR with a good chance of convection to continue thru the eve, and possibly overnight across northcentral LA. Steep low lvl lapse rates along with vigorous frontal boundary will have potential for stg gusty winds with some storms. This front will begin to move slowly later tonight as it loses steam and thus will carry isold pops into the morning on Tue across se portions of area. Overnight lows may dip below 70 degrees across nw portions of area although northerly winds of 10 to 15 mph behind front will minimize any chance of radiation cooling. Aftn highs to range thru the 80s on Tuesday with much lower humidity and refreshing nrly breeze. Better radiation cooling Tue night with overnight lows falling into lower to middle 60`s./07./ LONG TERM.../Wednesday through Monday/ It`s going to be hard to beat the kind of weather forecasted for the middle and late work week and this due in part to a deep trough of low pressure across the eastern third of the country with a strong ridge anchored across the Four Corners region of the country. It`s this flow that allowed a strong cold front to move through the Southern Plains and Lower Mississippi Valley and that front will push all the way into the Northern Gulf of Mexico by Thursday which is very unusual for late July. Also unusual is the temperatures we are expecting behind this boundary with highs Wed and Thu only in the middle to upper 80s and overnight lows in the lower to middle 60s. Would not be surprised to see a few locations squeak out lows in the upper 50s across the more protected areas of SW AR and SE OK, again, very pleasant for the end of July. Temps begin to moderate somewhat by Friday as the ridge across the Four Corners Region tries to retrograde slightly to the west with ridging becoming once again established across the Eastern Gulf of Mexico with a weak trough splitting the two ridges across the Middle Mississippi River Valley into the Northwest Gulf. It`s this weak trough or shear axis along with returning Gulf of Mexico moisture setting up across our region to produce diurnally driven convection this weekend into early next week. Also returning will be more late July-like temperatures with 90s for highs returning and 70s for lows. Enjoy the milder weather while it lasts, there is still a lot of summer left in 2019. 13 && .PRELIMINARY POINT TEMPS/POPS... SHV 71 86 63 86 / 30 10 0 0 MLU 72 83 61 85 / 50 10 0 0 DEQ 68 85 62 86 / 10 0 0 0 TXK 68 85 63 86 / 10 0 0 0 ELD 69 84 60 85 / 30 0 0 0 TYR 70 89 66 87 / 10 0 0 0 GGG 71 87 64 86 / 10 0 0 0 LFK 73 89 65 88 / 30 10 0 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 09/05
Area Forecast Discussion
National Weather Service Tucson AZ
259 PM MST Mon Jul 22 2019 .SYNOPSIS...Ample moisture and favorable flow will result in scattered to numerous thunderstorms this afternoon into tonight. Blowing dust due to thunderstorm gusts appear increasingly likely late this afternoon and early evening. A chance of showers and thunderstorms will continue Tuesday and into the upcoming weekend. && .DISCUSSION...Large scale pattern and mesoscale features remain favorable for organized thunderstorm activity with wet downburst potential and strong organized outflow. Decent easterly storm level flow with low level southerly inflow for 25-30kts of shear. Surface based and ML CAPEs in the 1200 to 1800 J/kg range and nice upper level diffluence. We had to wait an extra hour or so for sufficient insolation due to earlier debris cloud clearing out this morning. HRRR and UofA WRF models are doing pretty well again today and still suggest broad strong outflow pushing from Tucson to Phoenix late this afternoon into the evening. Our offices have a blowing dust advisory to set the stage with an eye out for possible warning levels below 1/4 mile. Marginal severe risk from SPC and Slight on the excessive rainfall outlook from WPC both look good. After a busy late afternoon and evening, some showers will linger embedded in the debris could overnight. For tomorrow, our high center remains consolidated near the 4-corners region with a nice easterly steering flow continuing for storms. Deterministic GEFS/ECMWF have a weak impulse under the high in southwest New Mexico shifting into SE AZ tomorrow afternoon. That, combined with an above average flow may be enough to reset for another solid chance of thunderstorms across the area tomorrow afternoon and evening. As we maintain this mid level easterly flow through mid week, it will weaken a little and entrain a little bit of dry air, but we should maintain enough lower level and boundary layer moisture to recycle into some afternoon thunderstorms. However, there may be days where they are not as well supported in valleys such as Wed/Thu. With the high center finally in a position where it wobbles back and forth overhead to northwest to northeast of us, the overall trend will be better than the past couple of weeks with up days and down days. && .AVIATION...Valid through 24/00Z. Scattered to numerous TSRA/SHRA starting from the White Mountains to the Huachucas will move westward to the west of KTUS. This will mainly affect KTUS, KOLS, and KSAD. Scattered to numerous -TSRA/- SHRA continuing area-wide tonight as well which will continue to affect KTUS and KOLS but should bring impacts to KDUG as well. Wind gusts up to 55 kts may occur with the strongest TSRA. Otherwise, cloud decks mainly 10k-15k ft MSL except MFVR cigs and vsbys and potentially brief IFR conditions with strongest TSRA this afternoon into tonight. Aside from tstm gusts, surface wind today KTUS vicinity westward nwly 8-16 kts with gusts near 20 kts. Surface wind today vicinity KSAD to KDUG ely to sely 8-18 kts with gusts near 25 kts. Surface wind area-wide by end of period ely/sely 8-18 kts with gusts to 25 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered to numerous thunderstorms continue throughout the afternoon and tonight. Scattered mainly afternoon and evening thunderstorms will prevail Tuesday into next Sunday. Expect gusty and erratic winds near thunderstorms. Otherwise, 20-foot winds Tuesday will be from the east to southeast mainly under 15 mph. 20- foot winds Wednesday into Sunday will be primarily terrain driven at less than 15 mph. && .TWC WATCHES/WARNINGS/ADVISORIES... Blowing Dust Advisory until 9 PM MST this evening for AZZ501-502- 504>506. && $$ Meyer/Pawlak Visit us on Facebook...Twitter...YouTube...and at
Area Forecast Discussion
National Weather Service Las Vegas NV
304 PM PDT Mon Jul 22 2019 .SYNOPSIS...Monsoon moisture will continue to spread into the region through Thursday which will result in a marked increase in clouds and humidity but also increased afternoon and evening thunderstorm activity. Less shower and thunderstorm coverage is expected over the weekend along with above normal temperatures. && .DISCUSSION...through next Monday. Transition into our seasonal monsoon pattern underway today as low/mid levels of the atmosphere continue to moisten from Las Vegas south. As of 2 pm, some stations within the Las Vegas valley have seen their surface dewpoints rise into the lower 50s. An area with dewpoints in the 60s still encompasses the lower Colorado River Valley. So far, instability has been lacking across Mohave and Clark Counties with light rain or virga occurring. As isolated thunderstorm has developed between Joshua Tree and 29 Palms. Gusty winds and lightning primary concerns with todays activity. Tonight: HRRR and other near term guidance suggests thunderstorm complexes that merge over central Arizona will eject an outflow boundary westward that will move into southeast Mohave County around midnight. The added lift from the boundary may be enough to tap into elevated instability. So, increased POPs between the 06z and 12z forecast hours tonight. Tuesday-Thursday: No much change to the forecast these days. Moisture will continue to stream northward into central Nevada Tuesday and linger through Thursday. Even as the lower levels moisten, inverted-V forecast soundings for Tuesday; slightly less indication for Wednesday support idea of gusty winds primary threat. Although, can rule out possibility of isolated heavy rain and flooding on Wednesday and Thursday. The higher humidity and cloud cover will lead to cooler highs and warmer overnight lows. Friday-Monday: Ensembles continue to support the idea of gradual decrease in convection coverage during the period. As the Four Corner high shifts back westward temperatures will rise back above normal. && .AVIATION...For McCarran...For this afternoon and evening, looking less likely for thunderstorms in the higher terrain to the west, so not anticipating gusty west winds at this time this evening. Expect winds to slowly turn southeast, with gusts to around 15kts possible. Tonight will start with typical southwest wind patterns and increasing mid to high level clouds. By early Tuesday morning, still watching the potential for a switch to the southeast around 12Z from a possible outflow out of Arizona. Did include the switch to the southeast in the TAF, however low confidence in wind speeds. If southeast winds do not make it to LAS, winds will remain southwest and then should become light and variable after 14Z. Low confidence in Tuesday forecast. Showers and thunderstorms should develop over southern NV, however location and timing is uncertain. Wind forecast Tuesday afternoon current reflects typical wind patterns, however this may change based on outflow winds from area thunderstorms. Slight chance thunderstorms move into the valley, mainly after 21Z. For the rest of southern Nevada, northwest Arizona and southeast California...Showers and thunderstorms will continue near DAG through the evening before dissipating this evening. Winds may become gusty and erratic base don how strong thunderstorms become and if outflows move through. Moderate confidence in the overnight forecast across the region. Showers and isolated thunderstorms may develop late this evening and overnight in Western AZ, which would rotate through IFP/EED around midnight if they develop. Did not include precip in the TAFs at this time due to low confidence. This area of showers and thunderstorms may rotate northward and effect southern NV as well by Tuesday morning. The other unknown overnight is whether or not an outflow pushed north and west out of Arizona. Best chance for gusty erratic winds would be in IFP/EED, where gusty southeast winds are possible. Outside of convection, expect typical wind patterns with i increasing mid to high level clouds. More thunderstorms are possible Tuesday afternoon, with low confidence in current TAF forecast. && .SPOTTER INFORMATION STATEMENT...As moisture continues to increase into the region. Spotters are encouraged to report any significant winds, hail and rainfall that produce impacts according to standard operating procedures. && $$ DISCUSSION...Pierce AVIATION...Wolf For more forecast information...see us on our webpage: or follow us on Facebook and Twitter