Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/06/16

Area Forecast Discussion
National Weather Service Tucson AZ
845 PM MST TUE JUL 5 2016

.SYNOPSIS...Isolated to scattered afternoon and evening
thunderstorms will prevail mainly east to south of Tucson through
Friday. A few thunderstorms may occur across the White Mountains and
far southeastern sections Saturday, then dry conditions area-wide
Monday into next Tuesday. Daytime temperatures will be quite close to
seasonal normals.

&&

.DISCUSSION...Still looking at a few showers and thunderstorms near
the International Border around KDUG. Otherwise, skies were mostly
clear late this evening. The current forecast calls for a little
more thunderstorm activity tomorrow and the next few days. This
looks reasonable based on the latest model solutions. Thus, no
updates necessary this evening.

&&

.AVIATION...VALID THRU 07/06Z.
Somewhat greater coverage of -TSRA/-SHRA will then occur Wednesday
afternoon, with isolated to scattered -TSRA/-SHRA mainly from KTUS
vicinity east and south to the New Mexico/International borders.
Mostly clear skies late tonight into Wednesday morning. Scattered to
broken clouds at 10k-15k ft msl Wednesday afternoon. Surface wind
Wednesday afternoon will generally be wly at 10-15 kts with gusts to
20 kts. Otherwise, surface wind will be variable in direction at
less than 10 kts. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Isolated to scattered showers and thunderstorms will
occur from Tucson eastward and southward Wednesday through Friday. A
few thunderstorms may occur across the White Mountains and far
southeastern sections Saturday, then dry conditions will prevail
area-wide Monday into Tuesday. Otherwise, 20-foot winds will
generally be terrain driven at less than 15 mph into early next week.

&&

.PREV DISCUSSION...Some increase in showers/tstms is
expected Wednesday into Friday, with the favored period during the
afternoon/evening hours. Have noted that the GFS continued to
befairly more robust to markedly more robust regarding precip
chances versus the NAM/ECMWF/CMC solutions. For this forecast
package, made only minor adjustments to the inherited gridded data
PoP fields.Thus, isolated to scattered showers/tstms from Tucson
eastward/southward Wednesday thru Friday with dry conditions across
western/central Pima County and south-central Pinal County.
Have maintained a slight chance of showers/ tstms Saturday across
the White Mountains and far southeastern sections.

Thereafter, the GFS/ECMWF/CMC were nearly identical with depicting a
closed upper low over the Pacific Northwest Sunday. A tighter mid-
level gradient should translate into stronger wly flow aloft, and
shunt deeper moisture well east of this forecast area. Although the
upper flow will weaken considerably by next Tuesday as high pressure
aloft builds over the area, dry conditions are expected to continue.
Thus, have continued with precip-free conditions area-wide Sunday
into next Tuesday. Expect only very minor daily temp changes, and
high temps will generally be within a couple of degs or so of normal
into early next week.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...None.

&&

$$

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  [top] Area Forecast Discussion National Weather Service Phoenix AZ 835 PM MST TUE JUL 5 2016 .SYNOPSIS... A break in the Monsoon pattern will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona next week Wednesday and Thursday, storm chances will be limited to southeast Arizona. Otherwise, expect dry conditions with near, to slightly above, normal temperatures. && .DISCUSSION... Another very quiet evening across our cwa, with westerly flow all the way through the column keeping monsoon moisture and thunderstorms well off to our south, mainly over extreme se AZ and northern Mexico. The combination of clear skies and a dry airmass (the 00z PSR sounding showing a pwat of only 0.81 inch) allowed temperatures to rise to near or slightly above 110F at the warmer lower desert locations again this afternoon. Tonight`s low appear that they will be very close to last night`s, in the upper-70 to mid-80 range across the lower deserts. Given current trends, other than some slight adjustments to the hourly temp/dewpoint grids, inherited forecasts are still looking good, and no updates are planned. && .PREVIOUS DISCUSSION... Rest of today through Thursday... A weak disturbance moving across AZ is producing some altocumulus plus there is some leftover lower level moisture over the higher terrain of AZ which has led to some flat cumulus development. Too stable and too little moisture for our area to see storms today. Expect they will be confined near the New Mexico border. For Wednesday and Thursday, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the broad subtropical high pressure region covering the southern CONUS/Mexico/Caribbean. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Hurricane Blas will be a non-factor. There will be some modest cooling...down to near normal/avg readings. Friday through Tuesday... The westerlies strengthen over the western states late in the week suppressing the axis of high pressure to our south . In the process, dry advection overspreads the region. This dry pattern stays in place through Tuesday. A proviso is that the deep moisture never goes exceedingly far away and remains over northwest Mexico. Thus if the intrusion of the westerlies winds up not being that strong and if convection over Sonora is more robust,then we may have more moisture to work with than anticipated. However, this scenario is really more relevant for southeast AZ as opposed to our forecast area. An upside to the influence of the westerlies is that temperatures are not looking to get out of hand despite the dry air. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Strong high pressure aloft and weak sfc pressure gradients to keep skies mainly clear through the taf period. Winds to mainly follow typical diurnal trends, with gusty afternoon westerly breezes at the Phx area terminals, gusty southerly afternoon winds at KBLH, and stronger westerly sundowner winds at KIPL again Wed evening. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Dry and persistent southwesterly flow aloft will maintain seasonably hot high temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds with gusts of 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Percha/AJ AVIATION...Percha FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Tucson AZ 330 PM MST TUE JUL 5 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions area-wide Monday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Isolated showers and thunderstorms will occur mainly near the international border south-to-southeast of Tucson this evening. These showers/tstms will end by midnight followed by clear skies or mostly clear skies late tonight into Wednesday morning. Some increase in showers/tstms is expected Wednesday into Friday, with the favored period during the afternoon/evening hours. Have noted that the GFS continued to be fairly more robust to markedly more robust regarding precip chances versus the NAM/ECMWF/CMC solutions. For this forecast package, made only minor adjustments to the inherited gridded data PoP fields. Thus, isolated to scattered showers/tstms from Tucson eastward/southward Wednesday thru Friday with dry conditions across western/central Pima County and south- central Pinal County. Have maintained a slight chance of showers/ tstms Saturday across the White Mountains and far southeastern sections. Thereafter, the GFS/ECMWF/CMC were nearly identical with depicting a closed upper low over the Pacific Northwest Sunday. A tighter mid- level gradient should translate into stronger wly flow aloft, and shunt deeper moisture well east of this forecast area. Although the upper flow will weaken considerably by next Tuesday as high pressure aloft builds over the area, dry conditions are expected to continue. Thus, have continued with precip-free conditions area-wide Sunday into next Tuesday. Expect only very minor daily temp changes, and high temps will generally be within a couple of degs or so of normal into early next week. && .AVIATION...VALID THRU 07/00Z. Expect isolated -TSRA/-SHRA this evening mainly near the international border southeast of KTUS. The best chance of -TSRA/-SHRA will be near the KDUG terminal, and perhaps further west and northwest to KFHU and KALK. However, the probability of occurrence is too low to include in the TAFs. Somewhat greater coverage of -TSRA/-SHRA will then occur Wednesday afternoon, with isolated to scattered -TSRA/-SHRA mainly from KTUS vicinity east and south to the New Mexico/International borders. Otherwise, west to northwest of KTUS expect clear skies to scattered clouds above 20k ft msl thru the period. KTUS vicinity east-to-south, a few to scattered clouds at 10k-15k ft msl into this evening followed by decreasing clouds with mostly clear skies late tonight into Wednesday morning. Scattered to broken clouds at 10k-15k ft msl Wednesday afternoon. Surface wind this evening and Wednesday afternoon will generally be wly at 10-15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Isolated to scattered showers and thunderstorms will occur from Tucson eastward and southward Wednesday through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions will prevail area-wide Monday into Tuesday. Otherwise, 20-foot winds will generally be terrain driven at less than 15 mph into early next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson Francis
  [top] Area Forecast Discussion National Weather Service Flagstaff AZ 321 PM MST TUE JUL 5 2016 .SYNOPSIS...West to southwest flow across the region will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains. && .DISCUSSION...Mostly dry weather with near average early July temperatures will persist through the 7 day forecast period. A trough moving through the Pacific Northwest will bring elevated southwest winds to the area Wednesday. Wind speeds will be slightly higher Wednesday than today, with gusts approaching 35 mph mainly from Flagstaff north. These increased winds combined with low afternoon humidity will cause near critical fire weather conditions generally from the I-40 corridor north. Dry west to southwest flow continues through the week with the only chance for afternoon thunderstorms over the White Mountains where enough moisture creeps in from the south. The active pattern continues to our north as an unseasonably cold low pressure system moves through the northwestern U.S. For Arizona, this will continue to bring dry and breezy weather with perhaps another notable increase in winds on Sunday. && .AVIATION...For the 00Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will diminish after sunset tonight and redevelop aft 16Z Wed. Wind gusts of 30-35 kts expected Wed afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A mostly dry west to southwest flow will continue. The only chance for afternoon thunderstorms will be over the White Mountains region Thursday. An increase in southwest winds combined with low humidity on Wednesday will result in near critical fire weather conditions generally from Flagstaff north. .Friday through Sunday...A chance for afternoon thunderstorms will continue across the White Mountains. Otherwise, dry weather with breezy afternoons and near average temperatures can be expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MCS AVIATION...MCS FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Phoenix AZ 249 PM MST TUE JUL 5 2016 .SYNOPSIS... A break in the Monsoon pattern will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona next week Wednesday and Thursday, storm chances will be limited to southeast Arizona. Otherwise, expect dry conditions with near, to slightly above, normal temperatures. && .DISCUSSION... Rest of today through Thursday... A weak disturbance moving across AZ is producing some altocumulus plus there is some leftover lower level moisture over the higher terrain of AZ which has led to some flat cumulus development. Too stable and too little moisture for our area to see storms today. Expect they will be confined near the New Mexico border. For Wednesday and Thursday, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the broad subtropical high pressure region covering the southern CONUS/Mexico/Caribbean. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Hurricane Blas will be a non-factor. There will be some modest cooling...down to near normal/avg readings. Friday through Tuesday... The westerlies strengthen over the western states late in the week suppressing the axis of high pressure to our south . In the process, dry advection overspreads the region. This dry pattern stays in place through Tuesday. A proviso is that the deep moisture never goes exceedingly far away and remains over northwest Mexico. Thus if the intrusion of the westerlies winds up not being that strong and if convection over Sonora is more robust,then we may have more moisture to work with than anticipated. However, this scenario is really more relevant for southeast AZ as opposed to our forecast area. An upside to the influence of the westerlies is that temperatures are not looking to get out of hand despite the dry air. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Winds will favor a normal diurnal sequence with occasional wind gusts of 15 to 20 kts. through the early evening--although more frequent wind gusts are likely for the southeast California terminals. Otherwise skies will remain mostly clear with few to sct mid and high clouds throughout the period. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Dry and persistent southwesterly flow aloft will maintain seasonably hot high temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds with gusts of 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...AJ AVIATION...Sawtelle FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Flagstaff AZ Issued by National Weather Service Las Vegas NV 911 AM MST TUE JUL 5 2016 .SYNOPSIS...Westerly flow across the southwest will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains. && .UPDATE...Overall the forecast is in good shape, with no updates planned this morning. Dry southwest flow remains in control with breezes expected each afternoon. && .PREV DISCUSSION /349 AM MST/...A drying west-southwesterly flow will persist over the next several days across northern Arizona. This will lead to fair and generally dry, but somewhat breezy, weather for much of the coming week. Near normal temperatures are also anticipated. While intermittent pushes of moisture may produce a slight chance for thunderstorms over far eastern Arizona, the pattern looks typical for an extended monsoonal break through the 7- day forecast. && .AVIATION...For the 18Z Package...Expect VFR conditions over the next 24 hrs, with breezy south to southwest winds each afternoon. A slight chance of an afternoon -SHRA/-TSRA over the White Mtns southeast of KSOW remains possible. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A drier southwesterly flow regime will limit any chance for a shower or storm to the White Mountains through Wednesday. Breezy afternoon winds will develop, with the highest wind speeds Wednesday as a trough passes north of the state. Thursday through Saturday...A chance for afternoon thunderstorms exists each day across the White Mountains. Elsewhere...dry weather with breezy afternoons expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...NWS Las Vegas PUBLIC...KD AVIATION...JJ FIRE WEATHER...JJ For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Phoenix AZ 904 AM MST TUE JUL 5 2016 .SYNOPSIS... Unseasonably dry air will continue to filter into the region as the pattern will transition away from a typical summer monsoon appearance. Temperatures will remain in a near normal range throughout the week under mostly clear skies. Only a modest chance of showers will exist through southeast and eastern Arizona during the midweek period, with virtually no chance of rain at lower elevations from central Arizona through southern California. && .DISCUSSION... Some of the larger circulation features over western North America and northeast Pacific include troughing centered over the Canadian Rockies (extending well into the NW CONUS), a large anticyclone west of the trough, and a very broad region of high pressure with an axis extending from west of Baja Mexico to east of Florida (containing multiple anticyclonic circulations). With troughing to the northwest and the axis of high pressure just to the south, our forecast area is largely within southwesterly flow aloft. There is a weak disturbance within that southwesterly flow which is producing some altocumulus. However, the 12Z soundings show that this disturbance will not be able to do much of anything else given how warm aloft we are and the drying that has taken place in the lower levels. Thus, we will have another very warm day with storm activity limited to areas well outside of our territory (near the New Mexico border). For Wed and Thu, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the high pressure region over/near us. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Made some subtle upward adjustments to the temperatures for today otherwise, forecasts in good shape. && .PREVIOUS DISCUSSION...Issued 145 am MST/PDT High pressure remains situated over northern Chihuahua early this morning while several shortwaves continue to carve out longwave troughing over the Pacific Northwest. This pattern configuration will only reinforce southwest/westerly flow throughout the SW Conus with an overall anti- cyclonic subsident regime. Boundary layer moisture also continues to be eroded with 00Z KPSR sounding data sampling an anemic 6 g/kg sfc-H7 mixing ratio, while KTWC data was only slightly more supportive for convective development at 8 g/kg. However, unusually warm temperatures aloft have been amplifying with H5 readings spiking at -4C and falling near the climatological 90th percentile capping any deep convection. This general pattern will essentially hold for the entire week keeping all but the southeast portions of Arizona devoid of thunderstorms (much less for all but afternoon fair weather mountain cumulus). The operational GFS still maintains a forecast of more robust Sonoran outflow advecting marginally better moisture profiles northward towards Pinal and Gila counties Wednesday and Thursday. However, trends in this operational run have definitely been towards a lower magnitude and less influential moisture push with only 8 g/kg materializing in the sfc-H7 layer. Thus, other than a brief shower/virga over far southeast Gila County, saw no justifiable reason to include any pops through the remainder of the forecast area into the weekend. One positive of this scenario is unlike most mid-monsoon season pattern breakdowns, this convectively inactive period will feature H5 heights depressed near 592dm and afternoon H8 temperatures only hovering between +25C and +29C. Typically, breaks in thunderstorm activity in July would result in near record highs, but model output emphatically supports temperatures near to only slightly above average throughout the week. In fact, spread among all post processed raw and numerical guidance persists in an extremely narrow range yielding excellent forecast confidence. Convection will continue to remain thoroughly absent from the forecast area well into next week as larger negative height anomalies develop over the Pacific Northwest. This will exacerbate westerly flow through the intermountain west and SW Conus further eliminating any sense of quality boundary layer moisture across the forecast area. There is strong evidence that sfc dewpoints through the weekend and into early next week fall into the 30s with total column Pwats descending towards 0.50 inches (climatologically near the 10th percentile for early/mid July). Thus, instead of entering deeper into monsoon flow of mid July, the atmosphere is actually regressing more towards an early June dry pattern. Though ensemble spread begins to grow towards the middle of next week, it may very well be until the end of next week at the earliest before sufficient moisture can return north and storm chances reenter the forecast picture. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Dry westerly flow aloft with only few to sct high clouds at all area terminals. Winds to mainly follow typical diurnal trends, with some afternoon gustiness likely, especially at KBLH. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Thursday through Monday: Dry southwesterly flow aloft will be in place through early next week. Minimum humidity values will be at or below 10% at most lower desert locations. Overnight recovery will be only fair. Surface winds will favor south-southwesterly in the afternoon and evening with gusts in the teens. Overall, the pattern is more characteristic of June rather than July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...AJ PREVIOUS DISCUSSION...MO AVIATION...Kuhlman FIRE WEATHER...AJ
Area Forecast Discussion National Weather Service Tucson AZ 900 AM MST TUE JUL 5 2016 .SYNOPSIS...A relatively dry air mass with westerly flow aloft will continue to limit thunderstorm coverage today. More moisture will increase thunderstorm chances the second half of the week. Another drier and warmer pattern moves in for next weekend. && .DISCUSSION...IR/Visible satellite imagery and surface observations depicted clear skies across much of southeast Arizona at this time. A few mid-level clouds were noted northwest of Tucson in the vicinity of Picacho Peak, and near the International border adjacent Cochise County. Dewpoints at lower elevations valid 15Z ranged from the 50s-lower 60s, and these temps were nearly identical to 24 hours ago. Surface temps valid 15Z were also essentially unchanged versus this time Monday. 05/12Z KTWC sounding total precip water value of 1.11 inches increased only 0.04 inch versus 24 hours ago. The column was nearly saturated around 600 mb but was quite dry in the surface-700 mb layer and above 500 mb. 05/12Z upper air plots depicted a 500 mb ridge axis that extended from west of northern Baja California eastward to Florida. Meanwhile, a belt of westerlies encompassed the northern CONUS with a 559 dm low centered over British Columbia. Light wly/swly flow aloft prevailed across southeast Arizona. The 12Z Univ. of AZ WRF-NAM was similar to the HRRR in depicting the initial development for showers/tstms late this morning or early this afternoon to occur near the Chiricahua Mountains in eastern Cochise County, or perhaps further west near the Huachuca Mountains in southwestern Cochise County. The bulk of showers/tstms later this afternoon and evening is progged to occur generally across the New Mexico bootheel, but some precip echoes were progged to be further west into about the southeast one quarter of Cochise County. Based on these solutions, see no reason to tamper with the official forecast that depicts isolated showers/tstms this afternoon/evening to occur from near Nogales eastward to the Chiricahua Mountains, or generally near the International border adjacent eastern Santa Cruz/ Cochise Counties. Dry conditions will prevail elsewhere, with high temps this afternoon virtually identical to temps achieved Monday afternoon. Please refer to the additional sections for further detail. && .AVIATION...VALID THRU 06/18Z. Expect isolated -TSRA/-SHRA this afternoon and evening mainly near the International border southeast of KTUS. The best chance of -TSRA/-SHRA will be near the KDUG terminal, and perhaps further west and northwest to KFHU and KALK. However, the probability of occurrence is too low to include in the TAFs. Otherwise, west to northwest of KTUS expect clear skies to scattered clouds above 20k ft msl thru the period. KTUS vicinity east-to-south few to scattered clouds at 10k-15k ft msl into this evening followed by decreasing clouds with mostly clear skies late tonight into early Wednesday morning. Surface wind this afternoon will generally be wly at 10-15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Enough moisture will linger for thunderstorms near the International border again today, with dry conditions elsewhere. Another brief push of moisture will bring increased coverage of showers and thunderstorms from near Tucson south and east Wednesday into Friday. Drying will then occur once again this weekend. 20-ft winds will generally favor diurnal patterns at 15 mph or less, with some enhancement in areas where afternoon westerly/northwesterly flow is the norm. && .PREV DISCUSSION /150 AM MST/...Water vapor imagery and 05/00Z upper- air plots show a sprawling ridge that extends generally west to east from the central Baja Peninsula across northern Mexico and into west Texas. This has resulted in a continuation of a dry westerly flow aloft across the desert southwest as evidenced on the 05/00Z KTWC sounding. The PW on the sounding was up a bit from 12 to 24 hours ago, with a value of 1.28 inches, which was about two-tenths of an inch greater. Both the CIRA LPW Total and the U of A GPS PW show a value as of 06Z of just a tad over an inch. Models indicate that the ridge to our south will shift eastward through early Wednesday to a position over the southern plains with the ridge axis extending westward across northern Mexico. As this shift occurs, return flow on the western flank of the ridge will allow moisture to increase during the middle to latter part of the week. Therefore, expect thunderstorm chances to increase mainly Wednesday into Thursday, with the focus for thunderstorms being from around Nogales to Douglas, with the activity spreading a bit farther north Thursday. For now it looks like the farthest northwestern extent of the storms will be around the Tucson area, with very little threat west and north of the city. Even so, it only looks like isolated coverage for the Tucson metro. However, this could change depending on what subsequent model runs indicate, so stay tuned. Confidence is not high at this point with the GFS being the most robust model in wanting to bring in the threat for storms, whereas the NAM and ECMWF, not so much. Just one example, looking at MOS POP numbers for Tucson, the NAM shows POPS in the single digits for Wednesday through Thursday, whereas the GFS has 12-hour POPS of 14, 39 and 21 percent for Wednesday, Wednesday night and Thursday, respectively. ECMWF is much closer to the NAM numbers. So, sorta went with a blend, but not yet close to the GFS values, especially for Wednesday night. With subsequent model runs, the forecast may change between now and the middle to latter part of the week. Confidence is moderate to high at this point that areas along the international border will see at least scattered convection. By the weekend a low pressure system will begin to affect the Pacific northwest as the ridge becomes reestablished to our south again, resulting in a drying trend for the weekend and into early next week. For Tucson, high temperatures will range from 2 to 4 degs above normal today and then near normal Wednesday through Friday before becoming around 2 to 4 degs above normal again for the weekend and early next week. Low temps will range from 4 to 6 degs above normal Wednesday morning, then around 2 to 4 degs above normal thereafter. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson DISCUSSION...Francis PREVIOUS DISCUSSION...Mollere AVIATION/FIRE WEATHER...French
AREA FORECAST DISCUSSION
National Weather Service Northern Indiana
741 PM EDT TUE JUL 5 2016 .SYNOPSIS... Issued at 406 PM EDT Tue Jul 5 2016 Continued gradual clearing is expected through the evening hours. Highs should reach into the lower to middle 80s. Low clouds and fog may redevelop later tonight. A frontal boundary will then bring chances for showers and thunderstorms back into the forecast Wednesday through Friday. Humidity levels will also increase during this time with highs well into the 80s each day. Next weekend will then feature drier and cooler conditions as high pressure builds into the Great Lakes region. && .SHORT TERM...(This Evening through Wednesday) Issued at 401 PM EDT Tue Jul 5 2016 quiet evening with continued gradual mixout of cu field. with convective focus well upstream have sided a bit more optimistic with only slight chance in far wrn/nwrn cwa mention needed only near daybreak. thereafter...uncertainty increases with outflow boundaries/convective debris canopy to potentially afford differential heating boundary for wed aftn/eve initiation in decidedly deeper high level theta-e regime. && .LONG TERM...(Wednesday Night through Tuesday) Issued at 401 PM EDT Tue Jul 5 2016 little substantive changes. persistent shra/tsra chances into at least friday amid cwa along southern base of peripheral zonal flow and lack of specfic timing of shortwaves precludes much detail...though concede diurnal trend...espcly friday aftn with potential favorable frontal timing. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 741 PM EDT Tue Jul 5 2016 General vfr conds xpcd this pd although pd of mvfr vsby restriction psbl overnight similar to last night given contd proxy of sfc ridge axis and clrg skies. Otrws upstream convn dvlpg acrs srn MN xpcd to pass well west acrs IL lt tonight. Waa wing downstream of this could potentially fire an isold-sct shra/tsra wed am but ltl confidence in this scenario and will defer for now. && .IWX Watches/Warnings/Advisories... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...murphy SHORT TERM...Murphy LONG TERM...Murphy AVIATION...T Visit us at www.weather.gov/iwx Follow us on Facebook...Twitter...and YouTube at: www.facebook.com/NWSNorthernIndiana www.twitter.com/nwsiwx www.youtube.com/NWSNorthernIndiana
Area Forecast Discussion National Weather Service Indianapolis IN 700 PM EDT TUE JUL 5 2016 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 113 PM EDT Tue Jul 5 2016 A warmer...more humid and unsettled weather pattern is expected to continue for the rest of the week. High pressure is expected to settle across the southeastern states...allowing a warmer and more humid southerly flow of air to preside across the Ohio Valley. As upper level weather disturbances push across this air mass...showers and thunderstorms will be expected from time to time. Typical summertime temperatures are expected into early next week. && .NEAR TERM /tonight/... Issued at 113 PM EDT Tue Jul 5 2016 Surface analysis early this afternoon shows a broad ridge of high pressure in place across the eastern United States. Low Pressure was found across the upper midwest. Warmer and more humid southerly flow was developing across the Indiana. Dew point temperatures have climbed back into the sticky upper 60s and lower 70s. Main forecast challenge tonight will be temps. 12Z 850mb analysis shows a thermal ridge in place ahead of low pressure over Minnesota and Lake Superior. This feature is expected to sag southward tonight amid the slight nw to zonal flow in place aloft across the northern CONUS. Water vapor continues to shows plenty of dry air in place across Indiana...Illinois and Missouri. Rapid refresh fails to develop much in the way of diurnal precip today as convective temps remain high. Furthermore with dry air in place aloft as seen by the water vapor imagery...will try to trend toward a dry forecast tonight. Given the expected warm air advection...southerly flow and very high dew points...will trend overnight lows at or above a model blend. && .SHORT TERM /Wednesday through Friday/... Issued at 113 PM EDT Tue Jul 5 2016 Relatively little chance is expected in the overall weather pattern through the period as the warm and humid air mass along with southerly surface flow remains in place across Indiana. Forecast Sounding suggest convective temps in the reachable upper 80s each day...thus afternoon diurnal convection cannot be ruled out. best chances for rain and storms will be on Wednesday afternoon and Wednesday night as a warm front approaches from the west. Time Heights show deep saturation and good lift. 310K GFS Isentropic surfaces show good upglide and high specific humidities in excess of 7 g/kg. Thus will trend highs pops during this time. Otherwise will stick close to a blend of pops...focusing chcs diurnally during the afternoons on Thursday...although confidence in this is not high as little support aloft is available. GFS suggest and upper low and short wave arriving in the Great lakes on Friday. This could provide a better triggering effect for showers/storms then as convective temps and moisture remain favorable. A blend on temps will suffice...may trend warmer in urban areas on lows for heat island effects. && .LONG TERM /Friday Night through Tuesday/... Issued at 250 PM EDT Tue Jul 5 2016 A cold front will move through Indiana late Friday as an upper trough digs into the great lakes. Models have trended in ending the chance of thunderstorms a little quicker and now only expect a slight chance of thunderstorms south half Friday evening. The front will stall over southern Kentucky and Tennessee over the weekend as weak high pressure moves into the great lakes. Went slightly cooler and dry over the weekend...although there may be a slight chance of thunderstorms south Sunday as the front starts to drift back to the north. Will mention a slight chance of thunderstorms all areas by Monday night as the front continues to drift north. Confidence for any storms next week is low as models also build an upper ridge across our region late in the long term period. Temperatures will be a degree or two below normal over the weekend and a couple of degrees above by day 7. Raised superblend temperatures slightly some period... but no significant changes were made. && .AVIATION /Discussion for 060000Z TAF issuance/... Issued at 652 PM EDT Tue Jul 5 2016 VFR through at least 6z with mostly clear skies and light variable winds. Models are still disagreeing over development of fog/low stratus during the overnight, but think potential looks greatest at KHUF and KBMG based on model soundings and forecast dewpoint depressions. Even so will keep them no lower than MVFR for now. Will start to develop after 6z at those sites, and after 8-9z at KIND. HRRR/NAM still showing potential for convection to reach KLAF after 9-10z but RAP is not on board. Went with a PROB30 there during the most likely time of convection. Any fog/low clouds should burn off around 13-14z Wednesday and then will start to see more convective potential arrive during the afternoon and evening. Should be more scattered during the late afternoon/evening and more widespread after 0z so will continue to leave out of surrounding sites for now. Winds will pick up to around 10-12 kts out of the southwest by late Wednesday morning after remaining less than 5 kts during the overnight. && .IND Watches/Warnings/Advisories... NONE. && $$ SYNOPSIS...PUMA NEAR TERM...PUMA SHORT TERM...PUMA LONG TERM....JH AVIATION...CP
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
645 PM CDT TUE JUL 5 2016 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Wednesday) Issued at 332 PM CDT TUE JUL 5 2016 Late this afternoon temperatures were in the late 90s with dewpoints int he the mid to upper 70s across east central KS, which has caused heat indices to be in the 110 to 114 degree range. The mixing was a bit deeper across the western counties where dewpoints have dropped into the upper 60s to lower 70s. Most numerical models do not show thunderstorms developing across the CWA this afternoon and evening, though MLCAPE values range from 4,000 to 5,000 J/KG. The HRRR is the only model that shows isolated thunderstorms developing across the CWA late this afternoon and evening but based on the lack of vertical CU development, I really do not see any boundary or minor vortmaxes that could help increase ascent for any thunderstorm development late this afternoon. Tonight, most models show scattered thunderstorms across northeast CO and the southern NE Panhandle this afternoon congealing into an MCS which will track east or southeast across the plains. The HRRR, NAM, and WRF solutions show the MCS tracking southeast across the CWA, though it may begin to weaken as it moves into northeast and east central KS late Tonight. If an MCS develops and maintains its intensity through the night then there will be a chance for heavy rainfall and potential damaging wind gusts along with penny to quarter size hail, with the better chance for strong to severe thunderstorms across north central KS during the early morning hours Wednesday. The exact track and the intensity of the MCS will not be known until it develops and begins to propagate to the southeast. Therefore, I went with chance pops after 6Z across the CWA but there will be higher pops wherever the MCS tracks. Wednesday, The morning thunderstorm complex will exit the eastern counties of the CWA by 15Z. Skies should clear from west to east across the CWA during the late morning and early afternoon hours. Highs should warm into the lower and mid 90s across the southern counties along with dewpoints holding in the mid 70s. If the MCS remains intense through the morning hours, then an outflow boundary may shift south of the CWA and the cloud cover may hold through most of the afternoon hours keeping Highs several degrees cooler. At this time I think we will clear out by afternoon and heat up into the mid 90s south of I-70. Therefore I have issued a heat advisory for areas along and south of I-70 from 12 Noon through 8 PM Wednesday where heat indices around 105 degrees during the afternoon hours. .LONG TERM...(Wednesday Night through Tuesday) Issued at 332 PM CDT TUE JUL 5 2016 Wednesday Night through Friday... Storms are expected to form in NW Kansas and SW Nebraska Wednesday evening and move east toward the area overnight. There is a chance some storms may make it into the northern portion of the CWA by late evening so low end PoPs are included during this time frame mainly north of I-70. Thunderstorm chances continue for Thursday as another shortwave is forecast to move through late afternoon into the evening. Soundings indicate a cap will be in place most of the afternoon Thursday, but with a front in the area and sufficient heating, the cap should degrade allowing a chance for storms to form. Models show high CAPE values over 3000 J/kg along with 0-6 km shear ranging between 25-35 knots. This makes organized convection possible with strong winds and gusty hail being the main hazard. Friday looks to have the best chance to be dry, although another shortwave near central Kansas may provide some focus for storms in east central Kansas during the afternoon Friday. As for temperatures during this time, the hottest day looks to be Thursday with heat indicies once again near 105 degrees due to dewpoints in the low 70s Thursday afternoon. The front finally makes it through the area this day allowing Friday to cool slightly with highs in the low 90s. Friday Night through Tuesday... Weak mid-level ridging will be in place at the beginning of the period. A frontal boundary is expected to stall in southern Kansas Saturday afternoon. This may be the focal point for thunderstorm development Saturday afternoon and evening. An amplified trough will be in place across the Western US late next weekend. EC and GFS differ on the effects from the trough. GFS much more bullish with strength of a shortwave trough lifting out from base of the trough. The unsettled pattern will continue through the remainder of the period as a potentially unstable atmosphere will be in place. As mid- level southwesterly flow settles in across the area, weak embedded waves will have the potential to spark thunderstorm activity for the remainder of the period. Temperatures will remain fairly seasonal with high temperatures in the upper 80s to lower 90s. With dew points near 70 degrees, heat index values will range from the mid- 90s to near 100 degrees for the entire extended period. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 645 PM CDT TUE JUL 5 2016 Have kept VCTS around 7-10Z for potential convective complex moving through. Confidence in its timing and occurrence are too low for prevailing TS. Minor wind shear potential exists around 10Z. && .TOP Watches/Warnings/Advisories... Heat Advisory until 8 PM CDT this evening for KSZ008>012-020>024- 026-034>040-054>056-058-059. Heat Advisory from 1 PM to 8 PM CDT Wednesday for KSZ034>039- 054>056-058-059. && $$ SHORT TERM...Gargan LONG TERM...Heller/Baerg AVIATION...65
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
324 AM CDT MON JUL 4 2016 .SHORT TERM...(Today and Tonight) Issued at 324 AM CDT MON JUL 4 2016 Sfc high pressure this morning was centered over southeast Nebraska. With the light winds and ample moisture near the sfc, widespread low stratus with some patchy light drizzle has developed and will linger through the morning. Patchy dense fog is likely in low lying areas where winds have become calm, otherwise all high resolution guidance keeps the boundary layer just mixed enough at around 5 to 8 mph to preclude widespread dense fog. Will continue to monitor trends in the winds, but do not plan to issue a fog advisory with this forecast. Sfc high pressure gradually slides southeast, keeping the area under mostly cloudy skies through the first half of the afternoon. Temporary ridging aloft behind the departing shortwave trough will preclude any precipitation through the period while a lee trough to the west veers winds to the south during the afternoon at 5 to 10 mph. Increasing warm advection with clearing skies over north central KS warms temps back to near normal in the upper 80s. Elsewhere, skies begin to clear in the mid to late afternoon with highs in the lower 80s. For this evening`s festivities, southerly winds weaken to near 5 mph as temperatures gradually fall into the low 70s Tuesday morning. Dry air advects southward within the boundary layer overnight, therefore chances for widespread stratus/fog are minimal. .LONG TERM...(Tuesday through Sunday) Issued at 324 AM CDT MON JUL 4 2016 There remains signs from the model solutions for a wave to move across the region late Tuesday and Tuesday night. Mid level lapse rates are forecast to be plenty steep enough for elevated instability but 0-6km shear is not all that impressive. So the expectation is for a possible MCS to impact the region mainly Tuesday night. However the models differ on where the possible MCS may track. Because of the poor consensus among the operational solutions, have kept POPs in the chance range. A similar set up is anticipated for Wednesday night in terms of airmass. But the forcing for storms is a little less obvious and still the models show different paths for any MCS. So the forecast keeps things dry for Wednesday with no real forcing or low level convergence. Additionally if there is an MCS Tuesday night, there would likely be decent subsidence in the wave of the system. Then the forecast has some small POPs for Wednesday night thinking better chances may be north of the forecast area. For Thursday night the GFS and ECMWF show a weak boundary moving into the area that could act as a focus for convection. Therefore have some chance POPs there as well. Temps for Tuesday through Thursday continue to look hot with mid and upper 90s forecast. The heat index continues to be the main concern as models continue to support values around 105 degrees. With the recent rains and evapotranspiration becoming a greater factor, dewpoints may have a difficult time mixing out during the heat of the day. Considered issuing an advisory for Tuesday but after collaborating with neighboring offices, will opt to let the day shift take a look at the 12Z model runs before issuing the advisory. For Friday through Sunday, it is difficult to pick a period where there shouldn`t be any precip chances. The GFS shows a decent elevated mixed layer capping the boundary layer and as such generates much less QPF across the area while the ECMWF shows various reasons for precip which are not entirely implausible. With this in mind and taking into account climatology a 20 to 30 percent chance on any given day, have stayed with a blend of the models with small chances for precip through the weekend. Temps are expected to be a bit cooler through the weekend with highs in the lower 90s as the thermal ridge moves to the west. && .AVIATION...(For the 06Z TAFS through 06Z Monday Night) Issued at 1116 PM CDT SUN JUL 3 2016 Weak high pressure will slowly move southeastward across eastern Kansas tonight and Monday morning. Moist atmosphere, wet ground and light winds will results in LIFR stratus and fog tonight, especially at TOP and FOE. High moving off to the southeast and winds switching around to the southeast by late Monday morning will results in gradually improving conditions with VFR expected by mid afternoon. && .TOP Watches/Warnings/Advisories... NONE. && $$ Happy 4th of July! SHORT TERM...Prieto LONG TERM...Wolters AVIATION...GDP
Area Forecast Discussion National Weather Service Wichita KS 318 AM CDT MON JUL 4 2016 .SHORT TERM...(Today through Thursday) Issued at 257 AM CDT Mon Jul 4 2016 A return to more seasonable temperatures can be expected across the area this afternoon but morning clouds & fog may linger over southeast Kansas dampening the diurnal climb once again. Shortwave ridging should result in dry weather conditions across the area as the low/mid lvl thermal ridge begins to expand eastward toward the Central Plains. A shortwave trough will approach on Tuesday bringing isolated storms to the area Tuesday afternoon & evening. 0-6km bulk shear of 30+ knots and mlcape exceeding 3000 j/kg may result in a severe storm or two but coverage is expected to remain limited given warm mid-lvl temperatures. As temperatures rise into the mid and upper 90s...heat indices will climb above the century mark with the highest values anticipated across southeast Kansas where dewpoint temperatures are expected to remain in the mid & upper 70s. A heat advisory may become necessary across portions of the area on Tuesday afternoon. Wednesday-Thursday...hot and dry weather is anticipated through the period with the potential for triple digits returning to some areas. Confidence in widespread 100+ degree temperatures remains low at this time given recent widespread precipitation & saturated soil conditions but areas that received less rain may rise above 100 degrees both days while much of the area will see heat indices exceeding 100 degrees. .LONG TERM...(Friday through Sunday) Issued at 257 AM CDT Mon Jul 4 2016 Another shortwave trough is progged to move over the Central Plains states on Friday bringing additional chances for showers and storms. Rising heights/increasing thickness will support rising temperatures as we move into the weekend with mostly dry weather conditions expected. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1119 PM CDT Sun Jul 3 2016 A combination of stratus build-down and radiational affects will promote IFR/LIFR CIGS and IFR VSBYS in fog overnight across much of central and eventually southeast Kansas. Surface ridge will gradually shift east from central into southeast Kansas early Monday morning with a return southerly flow developing across central Kansas by late morning into Monday afternoon. The fog and stratus CIGS will lift steadily from LIFR/IFR to MVFR by late Monday morning with VFR returning by the afternoon. A few showers will linger in the southeast corner of Kansas tonight, though expected to remain south of the KCNU terminal. KED && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 90 73 94 76 / 10 10 20 20 Hutchinson 89 72 95 75 / 10 10 20 20 Newton 88 72 94 75 / 10 10 20 20 ElDorado 87 72 94 76 / 0 10 20 20 Winfield-KWLD 91 73 95 78 / 0 10 20 20 Russell 92 70 97 72 / 10 10 20 20 Great Bend 92 70 96 72 / 10 10 20 20 Salina 88 71 97 75 / 10 10 20 30 McPherson 89 72 95 75 / 10 10 20 20 Coffeyville 89 74 94 77 / 10 10 10 20 Chanute 86 74 94 76 / 10 10 10 30 Iola 85 73 94 76 / 10 10 10 30 Parsons-KPPF 88 74 94 77 / 10 10 10 30 && .ICT Watches/Warnings/Advisories... None. && $$ SHORT TERM...MWM LONG TERM...MWM AVIATION...KED
Area Forecast Discussion National Weather Service Goodland KS 152 AM MDT MON JUL 4 2016 .SHORT TERM...(Today through Wednesday night) Issued at 146 AM MDT Mon Jul 4 2016 Across the Tri State region this morning...temperatures are ranging in the 60s w/ a mix of clear and cloudy skies. A low level cloud deck has blanketed the eastern half of the area this morning due to surface high pressure to our east creating a ESE surface gradient. Trend is for areal coverage of cloud cover to slowly shift east thru the morning hours as the surface ridge shifts in tandem. For the beginning of the week right into the midweek(Wed/Wed night) timeframe...the forecast area will see a return of hot conditions. H5/H7 ridging over the southern half of the country is going to set up a general zonal/westerly downslope flow from the Rockies. This in turn with lee-side troughing over the Front Range and surface high pressure remaining to the east...will aid in strong WAA into the region. Models do carry a few shortwave troughs across the region Tuesday and Wednesday in tandem with the lee-side trough exiting east into the Plains Region. Bulk of dynamics do remain north of the CWA closest to the main system...but do expect rw/trw activity to occur as these systems push east. Deep dry layer over the region will be hard to overcome as these systems approach...but enough instability expected to trigger convection nonetheless. Model parameters enough to warrant mention of Marginal Risk for severe wx by SPC for both Tuesday and Wednesday. Best chances look to occur on Tuesday as remnants of lee-side trough linger over the Central Plains providing focus for convection to fire up. For temps...with model 850 mb temps in the +28C to +32C range during the day for the next 72-hour period...looking for daytime highs to range in the 90s. Highs on Tuesday and Wednesday could be tempered a few degrees by expected clouds/precip. Overnight lows will range in the 60s to almost 70F in the eastern zones. Record highs for the Mon-Wed timeframe will range 103F to 111F...so not expecting any ties/records. Precip/Wx...areas of fog this morning for eastern zones expected to burn off/shift east in tandem with cloud cover movement and a shift to more SSW winds. Timing for convection Tues/Wed will focus on afternoon/early evening hrs especially for central/eastern zones. PW values are going to range from 0.75" to almost 1.25" during expected precip. Higher numbers east where closest to tapping into deeper Gulf moisture. Some storms that could develop might carry heavy rainfall. Other concern to follow going into midweek should no moisture fall...especially for western areas...will be the low RH values creeping into the upper teens and lower 20s...and thus potential Fire Wx issues. Winds will be tempered below criteria during this time...but should be monitored nonetheless. .LONG TERM...(Tuesday through Sunday) Issued at 151 AM MDT Mon Jul 4 2016 In the extended period the models are showing a upper level longwave trough with a tail end of a surface front moving through the region Thursday and Friday. This will produce a chance of showers and thunderstorms at the start of the period. Saturday, as the trough continues to move towards the east, a ridge will move over the region from the west. Saturday night will be another chance of showers and thunderstorms as the models show a shortwave trough moving within the upper level southwest flow and a surface boundary over the Kansas/Colorado border. Sunday is expected to dry out as the ridge continues to influence the region for the rest of the extended. Temperatures are expected to be in the lower 90s for most of the period. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1117 PM MDT Sun Jul 3 2016 At KGLD...VFR expected with light downslope winds veering from southwest overnight to northwest Monday morning. At KMCK...low clouds already developing in moist southeasterly flow. Expect ceilings to gradually lower overnight with LIFR or perhaps VLIFR around sunrise if fog manages to reduce visibilities as well. Conditions will improve by mid to late Monday morning with VFR thereafter. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JN LONG TERM...BW AVIATION...024
Area Forecast Discussion National Weather Service Goodland KS 146 AM MDT MON JUL 4 2016 .SHORT TERM...(Today through Wednesday night) Issued at 146 AM MDT Mon Jul 4 2016 Across the Tri State region this morning...temperatures are ranging in the 60s w/ a mix of clear and cloudy skies. A low level cloud deck has blanketed the eastern half of the area this morning due to surface high pressure to our east creating a ESE surface gradient. Trend is for areal coverage of cloud cover to slowly shift east thru the morning hours as the surface ridge shifts in tandem. For the beginning of the week right into the midweek(Wed/Wed night) timeframe...the forecast area will see a return of hot conditions. H5/H7 ridging over the southern half of the country is going to set up a general zonal/westerly downslope flow from the Rockies. This in turn with lee-side troughing over the Front Range and surface high pressure remaining to the east...will aid in strong WAA into the region. Models do carry a few shortwave troughs across the region Tuesday and Wednesday in tandem with the lee-side trough exiting east into the Plains Region. Bulk of dynamics do remain north of the CWA closest to the main system...but do expect rw/trw activity to occur as these systems push east. Deep dry layer over the region will be hard to overcome as these systems approach...but enough instability expected to trigger convection nonetheless. Model parameters enough to warrant mention of Marginal Risk for severe wx by SPC for both Tuesday and Wednesday. Best chances look to occur on Tuesday as remnants of lee-side trough linger over the Central Plains providing focus for convection to fire up. For temps...with model 850 mb temps in the +28C to +32C range during the day for the next 72-hour period...looking for daytime highs to range in the 90s. Highs on Tuesday and Wednesday could be tempered a few degrees by expected clouds/precip. Overnight lows will range in the 60s to almost 70F in the eastern zones. Record highs for the Mon-Wed timeframe will range 103F to 111F...so not expecting any ties/records. Precip/Wx...areas of fog this morning for eastern zones expected to burn off/shift east in tandem with cloud cover movement and a shift to more SSW winds. Timing for convection Tues/Wed will focus on afternoon/early evening hrs especially for central/eastern zones. PW values are going to range from 0.75" to almost 1.25" during expected precip. Higher numbers east where closest to tapping into deeper Gulf moisture. Some storms that could develop might carry heavy rainfall. Other concern to follow going into midweek should no moisture fall...especially for western areas...will be the low RH values creeping into the upper teens and lower 20s...and thus potential Fire Wx issues. Winds will be tempered below criteria during this time...but should be monitored nonetheless. .LONG TERM...(Monday night through Sunday) Issued at 213 PM MDT Sun Jul 3 2016 The extended period will be fairly active with precipitation chances possible everyday. Starting Monday night, the ridge gets pushed to the east fairly quickly with a trough starting to push in from the west. Precipitation chances continue into the evening and overnight hours over the western portions of the region due to the shortwave moving into the area. The upper level shortwave is slow moving, so Tuesday is looking to be impacted by the same one and PoPs are possible primarily in the eastern portions of the region. As the day continues another 700 mb shortwave moves into the western portions of the region bringing slight chances for precipitation during the evening hours. CAPEs reach the 1200-1500 J/kg range so some stronger storms are possible. Moving into Wednesday, a large portion of the region could see precipitation as yet another shortwave moves through the region on the east side of the trough. Thursday, as of current model runs, looks the most impressive for storm chances due to there being a cold front dipping down into the CWA from the north as the trough moves into the northern portion of the region. CAPEs get up to 1300 J/kg in area and bulk shear is in the 50-60 kt range. Once that trough passes us another ridge moves into the region and stays over the CWA through Saturday before another trough begins to push into the west. Friday and Saturday look similar, but Saturday night looks more impressive with a boundary along the Kansas, Colorado border and a shortwave moving over the area. Sunday is expected to dry out, for the most part, as a ridge moves into the region. Temperatures are expected to be in the 90s the entire period with a small drop on Thursday and Friday as the trough impacts the region. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1117 PM MDT Sun Jul 3 2016 At KGLD...VFR expected with light downslope winds veering from southwest overnight to northwest Monday morning. At KMCK...low clouds already developing in moist southeasterly flow. Expect ceilings to gradually lower overnight with LIFR or perhaps VLIFR around sunrise if fog manages to reduce visibilities as well. Conditions will improve by mid to late Monday morning with VFR thereafter. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JN LONG TERM...CLT AVIATION...024
Area Forecast Discussion National Weather Service Goodland KS 146 AM MDT MON JUL 4 2016 .SHORT TERM...(Today through Wednesday night) Issued at 146 AM MDT Mon Jul 4 2016 Across the Tri State region this morning...temperatures are ranging in the 60s w/ a mix of clear and cloudy skies. A low level cloud deck has blanketed the eastern half of the area this morning due to surface high pressure to our east creating a ESE surface gradient. Trend is for areal coverage of cloud cover to slowly shift east thru the morning hours as the surface ridge shifts in tandem. For the beginning of the week right into the midweek(Wed/Wed night) timeframe...the forecast area will see a return of hot conditions. H5/H7 ridging over the southern half of the country is going to set up a general zonal/westerly downslope flow from the Rockies. This in turn with lee-side troughing over the Front Range and surface high pressure remaining to the east...will aid in strong WAA into the region. Models do carry a few shortwave troughs across the region Tuesday and Wednesday in tandem with the lee-side trough exiting east into the Plains Region. Bulk of dynamics do remain north of the CWA closest to the main system...but do expect rw/trw activity to occur as these systems push east. Deep dry layer over the region will be hard to overcome as these systems approach...but enough instability expected to trigger convection nonetheless. Model parameters enough to warrant mention of Marginal Risk for severe wx by SPC for both Tuesday and Wednesday. Best chances look to occur on Tuesday as remnants of lee-side trough linger over the Central Plains providing focus for convection to fire up. For temps...with model 850 mb temps in the +28C to +32C range during the day for the next 72-hour period...looking for daytime highs to range in the 90s. Highs on Tuesday and Wednesday could be tempered a few degrees by expected clouds/precip. Overnight lows will range in the 60s to almost 70F in the eastern zones. Record highs for the Mon-Wed timeframe will range 103F to 111F...so not expecting any ties/records. Precip/Wx...areas of fog this morning for eastern zones expected to burn off/shift east in tandem with cloud cover movement and a shift to more SSW winds. Timing for convection Tues/Wed will focus on afternoon/early evening hrs especially for central/eastern zones. PW values are going to range from 0.75" to almost 1.25" during expected precip. Higher numbers east where closest to tapping into deeper Gulf moisture. Some storms that could develop might carry heavy rainfall. Other concern to follow going into midweek should no moisture fall...especially for western areas...will be the low RH values creeping into the upper teens and lower 20s...and thus potential Fire Wx issues. Winds will be tempered below criteria during this time...but should be monitored nonetheless. .LONG TERM...(Monday night through Sunday) Issued at 213 PM MDT Sun Jul 3 2016 The extended period will be fairly active with precipitation chances possible everyday. Starting Monday night, the ridge gets pushed to the east fairly quickly with a trough starting to push in from the west. Precipitation chances continue into the evening and overnight hours over the western portions of the region due to the shortwave moving into the area. The upper level shortwave is slow moving, so Tuesday is looking to be impacted by the same one and PoPs are possible primarily in the eastern portions of the region. As the day continues another 700 mb shortwave moves into the western portions of the region bringing slight chances for precipitation during the evening hours. CAPEs reach the 1200-1500 J/kg range so some stronger storms are possible. Moving into Wednesday, a large portion of the region could see precipitation as yet another shortwave moves through the region on the east side of the trough. Thursday, as of current model runs, looks the most impressive for storm chances due to there being a cold front dipping down into the CWA from the north as the trough moves into the northern portion of the region. CAPEs get up to 1300 J/kg in area and bulk shear is in the 50-60 kt range. Once that trough passes us another ridge moves into the region and stays over the CWA through Saturday before another trough begins to push into the west. Friday and Saturday look similar, but Saturday night looks more impressive with a boundary along the Kansas, Colorado border and a shortwave moving over the area. Sunday is expected to dry out, for the most part, as a ridge moves into the region. Temperatures are expected to be in the 90s the entire period with a small drop on Thursday and Friday as the trough impacts the region. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1117 PM MDT Sun Jul 3 2016 At KGLD...VFR expected with light downslope winds veering from southwest overnight to northwest Monday morning. At KMCK...low clouds already developing in moist southeasterly flow. Expect ceilings to gradually lower overnight with LIFR or perhaps VLIFR around sunrise if fog manages to reduce visibilities as well. Conditions will improve by mid to late Monday morning with VFR thereafter. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JN LONG TERM...CLT AVIATION...024
Area Forecast Discussion National Weather Service Dodge City KS 233 AM CDT MON JUL 4 2016 ...Updated short and long term sections... .SHORT TERM...(Today and tonight) Issued at 232 AM CDT Mon Jul 4 2016 Low clouds or patchy fog is expected east of Highway 283 this morning as winds remain light with ample moisture in the lower levels. Any low clouds or fog that do develop should burn off by the afternoon with mostly clear skies expected through the remainder of the day. A weak shortwave will approach western Kansas this evening into the overnight period but only a slight increase in cloud cover is anticipated. Lee troughing will develop today and continue through tonight leading to southerly winds felt across western Kansas. As for temperatures, highs today are progged to reach into the lower 90s with lows tonight around 70 degrees. .LONG TERM...(Tuesday through Sunday) Issued at 232 AM CDT Mon Jul 4 2016 An upper level ridge will be found above the southern United States and northern Mexico through the extended period. Flow above western Kansas will generally be zonal (west to east) through Wednesday then more southwest towards the end of the week as an upper level low moves through the Northern Rockies and Northern Plains. Towards the surface, a trough of low pressure will continue to be located west of the area through at least Wednesday bringing southerly winds to western Kansas. A weak shortwave is progged to move through the area Tuesday which will bring a slight chance of thunderstorms to central Kansas. Otherwise expect partly cloudy skies. A better chance of thunderstorms exists late this week into the weekend as the aforementioned disturbance affects western Kansas. This feature will also help push a cold front through the area shifting winds to more of a northerly direction Thursday. This will be short lived as troughing returns Friday into the weekend shifting winds back to a southerly direction. As for temperatures, highs Tuesday through Thursday look to reach into the mid to upper 90s then down slightly into the lower to mid 90s Friday into this weekend. Lows will generally range from the mid 60s across west central Kansas to lower 70s across south central Kansas. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1227 AM CDT Mon Jul 4 2016 Areas of fog or low level clouds are expected to form before sunrise this morning, mainly east of highway 83. This will bring MVFR to LIFR conditions to the DDC and HYS terminals. Visibilities and ceilings at GCK may remain higher and range from VFR to MVFR. Any fog or low clouds that do form should burn off by late morning with VFR conditions prevailing. Winds will be light overnight but from a southerly direction. Wind speeds then increase to around 10 knots by this afternoon. && .PRELIMINARY POINT TEMPS/POPS... DDC 92 70 95 70 / 10 10 20 10 GCK 92 68 95 67 / 10 10 10 10 EHA 92 67 97 68 / 10 10 10 10 LBL 94 69 98 69 / 10 10 10 10 HYS 91 70 97 69 / 10 10 20 20 P28 92 72 98 74 / 10 10 20 20 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Hovorka_42 LONG TERM...Hovorka_42 AVIATION...Hovorka_42
Area Forecast Discussion National Weather Service Dodge City KS 1246 AM CDT MON JUL 4 2016 ...Updated aviation section... .SHORT TERM...(This evening through Monday) Issued at 219 PM CDT Sun Jul 3 2016 Westerly flow across the Rockies will improve today as an upper level disturbance moves across eastern Kansas. Lingering low clouds this afternoon are expected to continue to erode through early tonight as light north winds begin to gradually veer to the east southeast. Some areas of fog will be possible late tonight across portions of western Kansas given the improving easterly up slope flow. At this time how dense the fog will be is somewhat unclear so am leaning away from issuing a dense fog advisory but will continue to look at this and adjust if needed later this afternoon. Late day convection that will be possible over southeast Colorado will spread southeast early this evening towards extreme southwest Kansas. The chance for convection this evening does not appear high but will keep small chances going west of highway 83 in extreme southwest Kansas. On Monday the latest guidance for highs stills appear to be a little too warm given the recent rainfall, despite the afternoon sunshine expected along with the warming 850mb temperatures between 00z Monday and 00z Tuesday. Will continue to follow the previous forecast and trend temperatures down several degrees Monday afternoon. .LONG TERM...(Monday night through Sunday) Issued at 219 PM CDT Sun Jul 3 2016 Warm air advection develops Monday night north of a surface boundary that will be located across the Panhandle of Texas and Oklahoma. A few models hinted at a subtle upper wave rippling across western Kansas early Monday night also. Given this will keep small chance in far south southwest Kansas near the Oklahoma border. On Tuesday an upper level trough, located over southern California at 12z Sunday, will exit the Rockies and begin to cross the Central Plains during the afternoon. This may give rise to a few afternoon or evening thunderstorms as it crosses western Kansas late day. Main limiting factor for storms Tuesday afternoon will be the warming forecast in the mid levels. Despite the warm mid level temperatures expected Tuesday afternoon am currently unable to completely rule out an isolated storm late day so will leave the slight chance for afternoon and evening storms ahead of this upper wave and east of the 10C to 14C 700mb temperature gradient. 850mb and 700mb temperatures continue to warm through Thursday so the chance for convection will continue to decrease for southwest Kansas. Temperatures are also expected to warm but unsure if temperatures will be as warm is what the 00z 850mb temperatures mixed down would suggest. Highs mainly in the mid 90s still appear to be reasonable. On Friday a surface cold front will drop south into western Kansas as an upper level disturbance will cross the northern plains. Another warm day with highs in the 90s can still be expected along and south of this front Friday afternoon while highs 5 to 10 degrees cooler will be possible north of this boundary. Exactly where this front will be late Friday however is somewhat unclear at this time so will follow the general trend of the CRExtendedFcst_Init for temperatures and precipitation chances Friday and Saturday. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1227 AM CDT Mon Jul 4 2016 Areas of fog or low level clouds are expected to form before sunrise this morning, mainly east of highway 83. This will bring MVFR to LIFR conditions to the DDC and HYS terminals. Visibilities and ceilings at GCK may remain higher and range from VFR to MVFR. Any fog or low clouds that do form should burn off by late morning with VFR conditions prevailing. Winds will be light overnight but from a southerly direction. Wind speeds then increase to around 10 knots by this afternoon. && .PRELIMINARY POINT TEMPS/POPS... DDC 64 92 70 96 / 10 10 10 20 GCK 63 92 68 96 / 10 10 10 10 EHA 64 92 67 98 / 20 10 10 10 LBL 65 94 69 98 / 10 10 10 10 HYS 62 91 70 96 / 10 10 10 20 P28 65 92 72 97 / 10 10 10 20 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Hovorka_42
Area Forecast Discussion National Weather Service Dodge City KS 1246 AM CDT MON JUL 4 2016 ...Updated aviation section... .SHORT TERM...(This evening through Monday) Issued at 219 PM CDT Sun Jul 3 2016 Westerly flow across the Rockies will improve today as an upper level disturbance moves across eastern Kansas. Lingering low clouds this afternoon are expected to continue to erode through early tonight as light north winds begin to gradually veer to the east southeast. Some areas of fog will be possible late tonight across portions of western Kansas given the improving easterly up slope flow. At this time how dense the fog will be is somewhat unclear so am leaning away from issuing a dense fog advisory but will continue to look at this and adjust if needed later this afternoon. Late day convection that will be possible over southeast Colorado will spread southeast early this evening towards extreme southwest Kansas. The chance for convection this evening does not appear high but will keep small chances going west of highway 83 in extreme southwest Kansas. On Monday the latest guidance for highs stills appear to be a little too warm given the recent rainfall, despite the afternoon sunshine expected along with the warming 850mb temperatures between 00z Monday and 00z Tuesday. Will continue to follow the previous forecast and trend temperatures down several degrees Monday afternoon. .LONG TERM...(Monday night through Sunday) Issued at 219 PM CDT Sun Jul 3 2016 Warm air advection develops Monday night north of a surface boundary that will be located across the Panhandle of Texas and Oklahoma. A few models hinted at a subtle upper wave rippling across western Kansas early Monday night also. Given this will keep small chance in far south southwest Kansas near the Oklahoma border. On Tuesday an upper level trough, located over southern California at 12z Sunday, will exit the Rockies and begin to cross the Central Plains during the afternoon. This may give rise to a few afternoon or evening thunderstorms as it crosses western Kansas late day. Main limiting factor for storms Tuesday afternoon will be the warming forecast in the mid levels. Despite the warm mid level temperatures expected Tuesday afternoon am currently unable to completely rule out an isolated storm late day so will leave the slight chance for afternoon and evening storms ahead of this upper wave and east of the 10C to 14C 700mb temperature gradient. 850mb and 700mb temperatures continue to warm through Thursday so the chance for convection will continue to decrease for southwest Kansas. Temperatures are also expected to warm but unsure if temperatures will be as warm is what the 00z 850mb temperatures mixed down would suggest. Highs mainly in the mid 90s still appear to be reasonable. On Friday a surface cold front will drop south into western Kansas as an upper level disturbance will cross the northern plains. Another warm day with highs in the 90s can still be expected along and south of this front Friday afternoon while highs 5 to 10 degrees cooler will be possible north of this boundary. Exactly where this front will be late Friday however is somewhat unclear at this time so will follow the general trend of the CRExtendedFcst_Init for temperatures and precipitation chances Friday and Saturday. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1227 AM CDT Mon Jul 4 2016 Areas of fog or low level clouds are expected to form before sunrise this morning, mainly east of highway 83. This will bring MVFR to LIFR conditions to the DDC and HYS terminals. Visibilities and ceilings at GCK may remain higher and range from VFR to MVFR. Any fog or low clouds that do form should burn off by late morning with VFR conditions prevailing. Winds will be light overnight but from a southerly direction. Wind speeds then increase to around 10 knots by this afternoon. && .PRELIMINARY POINT TEMPS/POPS... DDC 64 92 70 96 / 10 10 10 20 GCK 63 92 68 96 / 10 10 10 10 EHA 64 92 67 98 / 20 10 10 10 LBL 65 94 69 98 / 10 10 10 10 HYS 62 91 70 96 / 10 10 10 20 P28 65 92 72 97 / 10 10 10 20 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Hovorka_42
Area Forecast Discussion National Weather Service Goodland KS 1122 PM MDT SUN JUL 3 2016 .SHORT TERM...(This evening through Monday) Issued at 213 PM MDT Sun Jul 3 2016 Currently across the Tri-State area there is an upper level trough beginning to move east out of the region. As the trough continues to move east through the area clouds will begin to decrease. Temperatures are in the 70s/80s across the region with variable winds at less than 10 mph. The latest model runs of the NAM and HRRR have chances for PoPs this afternoon over the far southwestern portions (possibly into the northwestern portions) of the region as a weak shortwave moves over the CWA. CAPES will get to around 1500 J/kg but bulk shear is not impressive. The remainder of the night is expected to be dry. Around midnight MDT, fog is expected to form over areas along and east of Hwy 83. The SREF and NAM models have the fog lasting until around 13/14Z Monday morning. A ridge will move over the CWA Monday in the wake of the exiting trough. This will bring with it warmer temperatures in the 90s. There are slight chances for precipitation in the far western portion of the region in the late afternoon as an upper level shortwave moves towards the region. .LONG TERM...(Monday night through Sunday) Issued at 213 PM MDT Sun Jul 3 2016 The extended period will be fairly active with precipitation chances possible everyday. Starting Monday night, the ridge gets pushed to the east fairly quickly with a trough starting to push in from the west. Precipitation chances continue into the evening and overnight hours over the western portions of the region due to the shortwave moving into the area. The upper level shortwave is slow moving, so Tuesday is looking to be impacted by the same one and PoPs are possible primarily in the eastern portions of the region. As the day continues another 700 mb shortwave moves into the western portions of the region bringing slight chances for precipitation during the evening hours. CAPEs reach the 1200-1500 J/kg range so some stronger storms are possible. Moving into Wednesday, a large portion of the region could see precipitation as yet another shortwave moves through the region on the east side of the trough. Thursday, as of current model runs, looks the most impressive for storm chances due to there being a cold front dipping down into the CWA from the north as the trough moves into the northern portion of the region. CAPEs get up to 1300 J/kg in area and bulk shear is in the 50-60 kt range. Once that trough passes us another ridge moves into the region and stays over the CWA through Saturday before another trough begins to push into the west. Friday and Saturday look similar, but Saturday night looks more impressive with a boundary along the Kansas, Colorado border and a shortwave moving over the area. Sunday is expected to dry out, for the most part, as a ridge moves into the region. Temperatures are expected to be in the 90s the entire period with a small drop on Thursday and Friday as the trough impacts the region. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1117 PM MDT Sun Jul 3 2016 At KGLD...VFR expected with light downslope winds veering from southwest overnight to northwest Monday morning. At KMCK...low clouds already developing in moist southeasterly flow. Expect ceilings to gradually lower overnight with LIFR or perhaps VLIFR around sunrise if fog manages to reduce visibilities as well. Conditions will improve by mid to late Monday morning with VFR thereafter. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...CLT LONG TERM...CLT AVIATION...024
AREA FORECAST DISCUSSION
National Weather Service New Orleans LA
130 PM CDT MON JUL 4 2016 .AVIATION... Biggest impact over the next few hours will be showers and thunderstorms. The bulk of activity is currently moving across an area along a line northwest of a KBTR to KMCB line. These storms are moving quite briskly at 30+ knots and likely have wind gusts around that speed as well. Some storms could spread southeast of the current location but not expecting as much coverage there. Otherwise...vfr conditions will prevail through the overnight period with light to calm winds. MEFFER && .PRELIMINARY POINT TEMPS/POPS... MCB 76 93 74 93 / 20 20 10 20 BTR 77 95 77 94 / 10 10 10 20 ASD 78 93 77 93 / 10 10 10 20 MSY 79 93 79 94 / 10 10 10 20 GPT 80 93 79 92 / 10 10 10 20 PQL 76 91 77 92 / 10 10 10 20 && .LIX Watches/Warnings/Advisories... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion National Weather Service Lake Charles LA 1231 PM CDT MON JUL 4 2016 .AVIATION... Heating today combined with precip wtr around 1.9 inches and the approach of an upr lvl shrtwv fm the nw will support storm dvlpmntin se Tx and srn La thru the late aftn hrs. ATTM... AEX appears to be the Taf lctn w/ the highest potential for storm actvty. This will shift down into s-cntrl La drg the late aftn hrs...LFT and ARA. Storms ending around or just aftr ss... all TAF sites going VFR thereafter. && .PREV DISCUSSION... /issued 1141 AM CDT MON JUL 4 2016/ UPDATE... Cluster of storms now moving into e cntl TX has been showing signs of weakening the past few volume scans. This cluster is associated with an impulse aloft that will cross the area today. Additional sctd convection beginning to develop ahead of this complex, and this should continue through the aftn. Recent ARW has backed off on convective coverage fm its previous run while latest HRRR runs still indicate at least sctd coverage through the aftn. Adjusted POPs with a blend of recent HRRR guidance for the remainder of the day, and may need to fine tune further as things evolve. The good news is that these showers and storms should help moderate temperatures for some of the Independence Day celebrations today. Tweaked hourly temps and dewpoints to bring in line with recent obs, with minor adjustments through the aftn. This still keeps heat index values below advisory criteria except for an isltd spot or two. Convection expected to decrease by evening with the loss of daytime heating. Things should be fairly clear for evening fireworks displays although warm and muggy conditions will continue. 24 PREV DISCUSSION... /issued 659 AM CDT MON JUL 4 2016/ DISCUSSION... For 12z TAF issuance. AVIATION... VFR conditions are expected through most if not all the period. Two main issues may aid in precipitation development. First...slightly enhanced southerly flow had increased shower activity offshore early this morning. This activity has dissipated but believe isolated coverage of showers and storms will continue today. This will affect mainly BPT and LCH through the morning and over LFT and ARA later today. Also...MCS across north Texas will move southeast through the morning hours and may aid in bringing scattered thunderstorm activity to central Louisiana. There is some uncertainty on the impact of this system so for now will have VCTS for AEX this afternoon. Activity should dissipate by early evening. KLCH VWP is showing winds near 30 knots just above the surface. Winds will be somewhat higher than the past few days...potentially gusting to near 20 mph this afternoon. PREV DISCUSSION... /issued 342 AM CDT MON JUL 4 2016/ DISCUSSION... Additional information for the coastal waters below. MARINE... Will be extending the small craft exercise caution headline for the coastal waters from High Island to Cameron through Tuesday morning. Winds will be in the 15 to 20 knot range throughout the period. The exercise caution headline will be dropped at 7 am this morning for the Cameron to Intracoastal City coastal waters. PREV DISCUSSION... /issued 329 AM CDT MON JUL 4 2016/ DISCUSSION... Seeing a few showers developing off the Texas coast this early morning. Some of them are moving onshore and dissipating along or south of the I-10 corridor of SE TX and SW LA. Meanwhile...a MCS is seen in north central TX. All of this means there is a better chance of seeing some rain today...albeit only a 20 to 30 percent expectation at this point. Typically these nocturnal offshore showers dont last too far past daybreak...but models all show a mid-level shortwave coming down to our region this afternoon...so there may be better coverage than currently advertised...so stay tuned. As for todays high temperatures...expecting them to top out in the mid to upper 90s...unless there is a better rain coverage and it will be a little bit lower. Based on afternoon dew point forecast...max afternoon heat indices are in the 104 to 107 range...so just below heat advisory criteria. For the remainder of the week...it looks like there will be a small chance for showers and thunderstorms each day...with similar temperatures each day...highs in the 90s...lows in the 70s. Max heat indices holding right below heat advisory criteria...but irregardless...people should take precautions during the hottest time of the day...drink plenty of water...and minimize the length of time outdoors in the afternoons. && .PRELIMINARY POINT TEMPS/POPS... AEX 77 96 77 96 / 10 20 10 20 LCH 81 93 80 93 / 10 20 10 20 LFT 80 94 80 94 / 10 20 10 20 BPT 80 93 80 93 / 10 20 10 20 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...SMALL CRAFT EXERCISE CAUTION through Tuesday morning for GMZ450- 470. && $$ AVIATION...19 Area Forecast Discussion National Weather Service Phoenix AZ 150 AM MST WED JUL 6 2016 .SYNOPSIS... A break in thunderstorm activity with near average temperatures will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona today and Thursday, thunderstorm chances will be limited to southeast Arizona. Unusually quiet weather may persist through all of next week before any storms can move north once again. && .DISCUSSION... A thunderstorm complex over central Sonora associated with a weak inverted trough has largely dissipated early this evening, however has essentially bifurcated ridging aloft with one high pressure center shifting into west Texas while a western branch remains situated over far SE Arizona. Deep westerly flow throughout the vast majority of Arizona over the past 48 hours has progressively eroded moisture with both 00Z KPSR and KTWC sounding data sampling only 5 g/kg within the boundary layer and total column pwats falling near 0.75 inches. However, the degenerated Sonoran convective complex has created a pool of more substantial moisture which will partially bleed north across the international border in weak southwest flow today and Thursday. The first signs of this moisture intrusion can be seen in overnight KOLS observations with enhanced south winds and sfc dewpoints jumping over 60F. Forecast BUFR soundings resoundingly show some of this shallow moisture advecting north into the Phoenix area later this morning, and eventually deeper 8-9 g/kg sfc-H7 profiles enveloping much of the eastern third of the forecast area this afternoon. However, temperatures in the H7-H5 layer remain unseasonably warm under a general anti-cyclonic subsident flow regime leaving minimal instability and notable Cinh. While a stray shower could conceivably clip through higher terrain areas of southern Gila county, ensemble probabilities barely breach single digits through Thursday before dropping off completely heading into the weekend. The most notable weather feature locally through the weekend and into early next week is actually the complete lack of weather and thunderstorm activity. Deep negative height anomalies (around 2 normalized standard deviations below average) will propagate from the Pacific NW into the Great Basin with intense jet energy punching over the Sierra chain towards the central Rockies. Essentially every NAEFS member shows this scenario where the mid and upper tropospheric u-wind component becomes anomalously strong and within a climatologically rare threshold for mid July. Unlike much of the summer season, forecast confidence is exceedingly high and so much so as to assign absolutely no chance of rainfall for the entire Sat- Wed time frame as aggressive drying spreads through the atmospheric column. Furthermore with this increased westerly flow and depressed troughing pattern, H5 heights will languish only around 590dm yielding temperatures very close to the seasonal climatology. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Strong high pressure aloft and weak sfc pressure gradients to keep skies mainly clear through the taf period. Winds to mainly follow typical diurnal trends, with gusty afternoon westerly breezes at the Phx area terminals, gusty southerly afternoon winds at KBLH, and stronger westerly sundowner winds at KIPL again Wed evening. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Friday through Tuesday: Dry and persistent southwesterly flow will maintain seasonable temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds peaking at 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...MO AVIATION...Percha FIRE WEATHER...Sawtelle
  [top] Area Forecast Discussion National Weather Service Tucson AZ 145 AM MST WED JUL 6 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions nearly area- wide Sunday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Water vapor imagery and 06/00Z upper-air plots continue to show an east to west oriented ridge axis that extends from west Texas across northern Chihuahua Mexico and into south central Sonora and across central Baja. IR satellite imagery shows mostly clear skies across Arizona with a decaying storm complex to our south over eastern and southern portions of Sonora and northwestern parts of Chihuahua. The current synoptic setup continues to result in a dry westerly flow aloft across the Desert Southwest. The PW from the 06/00Z KTWC sounding was only 0.76 inches, compared to 1.28 inches from 24 hours ago. The U of A GPS PW for Tucson as of 05Z was just a tad above 0.75 inches, while the 06Z CIRA LPW Total was 0.8 inches. However, this is about to change as the CIRA LPW Total shows values of over 1.5 inches just to the south of the Cochise county border. In addition, values of 2.0+ inches can be seen near and to the east of MMHO (Hermosillo, Mexico) and values approaching 3 inches over southern Sonora. That said, the GFS has been advertising a fairly significant increase in moisture and thus POPS for today through Thursday as return flow along the western portion of the ridge ushers in moisture. The latest model runs are beginning to show better agreement than the past few days. The 06/00Z run of the NAM shows a very significant increase in the POP numbers from just the 05/12Z run, going from 3 percent for Tucson this afternoon to 34 percent. The GFS POP numbers have maintained consistency with values of around 20-30 percent for this afternoon and evening and continuing a solid chance category POPs through Thursday. ECMWF shows a slight increase from single digits to the slight chance category through Friday. At any rate, the 06/00Z run of the U of A WRF/NAM shows development over southwestern Cochise county by around Noon today and spreading into eastern Santa Cruz county and eastern Pima by late in the afternoon and/or early evening. The WRF/GFS shows initial development in the same general location, but more intense and spreading farther north into the Tucson metro and perhaps into central parts of Pima county. Based on all of this recent information, I did increase POPs for today through Thursday. Confidence is moderate to high that at least scattered storms will develop from around the Nogales area toward Douglas and eastward. The tricky part is just how far to the north/northwest will the convection develop. There will be a fairly tight POP gradient across my forecast area into the Phoenix area where they are showing virtually no chance of precipitation. I did adjust the forecast to show isolated activity today for Tucson, but depending on just how quickly the moisture moves in and what the 06/12Z KTWC sounding reveals will help determine if that category of POP is too low, or not. Day shift will have to see how things evolve and may have to make adjustments to increase POPs farther north and west than what I currently have in the forecast. The threat for showers and thunderstorms will diminish Friday, with most of the threat along the border with New Mexico and between Nogales and Douglas, but even then only isolated activity expected. Virtually no threat of storms Saturday through early next week as the ridge sets up to our south again, resulting in a dry south to westerly flow aloft. For Tucson, high and low temperatures will generally be at or slightly above normal through the forecast period. && .AVIATION...VALID THRU 07/12Z. SCT clouds at 8-12k ft AGL with BKN conditions mainly S and E of KTUS this afternoon/evening. Isolated-scattered -SHRA/-TSRA this afternoon mainly E of a KTUS-KOLS line, with some producing gusty winds and brief MVFR conditions. Otherwise, sfc winds will generally be terrain driven at 12 kts or less this morning, becoming wly/swly at 10-14 kts with gusts to around 20 kts this afternoon. Light and terrain driven winds will then resume during the overnight hours. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect better coverage of showers and storms today through Friday, with some developing as far north as the I-10 corridor including Tucson. Storms will be capable of producing gusty and erratic winds to 40 mph. Drying will then occur once again this weekend. Outside of convection, 20-ft winds will generally favor diurnal patterns at 15 mph or less, with some enhancement in areas where afternoon westerly/northwesterly flow is the norm. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...Mollere AVIATION/FIRE WEATHER...French Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Tucson AZ 145 AM MST WED JUL 6 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions nearly area- wide Sunday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Water vapor imagery and 06/00Z upper-air plots continue to show an east to west oriented ridge axis that extends from west Texas across northern Chihuahua Mexico and into south central Sonora and across central Baja. IR satellite imagery shows mostly clear skies across Arizona with a decaying storm complex to our south over eastern and southern portions of Sonora and northwestern parts of Chihuahua. The current synoptic setup continues to result in a dry westerly flow aloft across the Desert Southwest. The PW from the 06/00Z KTWC sounding was only 0.76 inches, compared to 1.28 inches from 24 hours ago. The U of A GPS PW for Tucson as of 05Z was just a tad above 0.75 inches, while the 06Z CIRA LPW Total was 0.8 inches. However, this is about to change as the CIRA LPW Total shows values of over 1.5 inches just to the south of the Cochise county border. In addition, values of 2.0+ inches can be seen near and to the east of MMHO (Hermosillo, Mexico) and values approaching 3 inches over southern Sonora. That said, the GFS has been advertising a fairly significant increase in moisture and thus POPS for today through Thursday as return flow along the western portion of the ridge ushers in moisture. The latest model runs are beginning to show better agreement than the past few days. The 06/00Z run of the NAM shows a very significant increase in the POP numbers from just the 05/12Z run, going from 3 percent for Tucson this afternoon to 34 percent. The GFS POP numbers have maintained consistency with values of around 20-30 percent for this afternoon and evening and continuing a solid chance category POPs through Thursday. ECMWF shows a slight increase from single digits to the slight chance category through Friday. At any rate, the 06/00Z run of the U of A WRF/NAM shows development over southwestern Cochise county by around Noon today and spreading into eastern Santa Cruz county and eastern Pima by late in the afternoon and/or early evening. The WRF/GFS shows initial development in the same general location, but more intense and spreading farther north into the Tucson metro and perhaps into central parts of Pima county. Based on all of this recent information, I did increase POPs for today through Thursday. Confidence is moderate to high that at least scattered storms will develop from around the Nogales area toward Douglas and eastward. The tricky part is just how far to the north/northwest will the convection develop. There will be a fairly tight POP gradient across my forecast area into the Phoenix area where they are showing virtually no chance of precipitation. I did adjust the forecast to show isolated activity today for Tucson, but depending on just how quickly the moisture moves in and what the 06/12Z KTWC sounding reveals will help determine if that category of POP is too low, or not. Day shift will have to see how things evolve and may have to make adjustments to increase POPs farther north and west than what I currently have in the forecast. The threat for showers and thunderstorms will diminish Friday, with most of the threat along the border with New Mexico and between Nogales and Douglas, but even then only isolated activity expected. Virtually no threat of storms Saturday through early next week as the ridge sets up to our south again, resulting in a dry south to westerly flow aloft. For Tucson, high and low temperatures will generally be at or slightly above normal through the forecast period. && .AVIATION...VALID THRU 07/12Z. SCT clouds at 8-12k ft AGL with BKN conditions mainly S and E of KTUS this afternoon/evening. Isolated-scattered -SHRA/-TSRA this afternoon mainly E of a KTUS-KOLS line, with some producing gusty winds and brief MVFR conditions. Otherwise, sfc winds will generally be terrain driven at 12 kts or less this morning, becoming wly/swly at 10-14 kts with gusts to around 20 kts this afternoon. Light and terrain driven winds will then resume during the overnight hours. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect better coverage of showers and storms today through Friday, with some developing as far north as the I-10 corridor including Tucson. Storms will be capable of producing gusty and erratic winds to 40 mph. Drying will then occur once again this weekend. Outside of convection, 20-ft winds will generally favor diurnal patterns at 15 mph or less, with some enhancement in areas where afternoon westerly/northwesterly flow is the norm. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...Mollere AVIATION/FIRE WEATHER...French Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
  [top] Area Forecast Discussion National Weather Service Flagstaff AZ 1012 PM MST TUE JUL 5 2016 .SYNOPSIS...West to southwest flow across the region will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains and portions of northern Gila county Thursday through Saturday. && .DISCUSSION...Winds have dropped off this evening, and updates were made to reduce the winds. Cloud cover was also reduced for the overnight time period. Breezy to windy conditions develop on Wednesday as a trough goes by to the north. Near critical fire weather conditions will be possible along and west northwest of a line from Prescott to Winslow to Kayenta. && .PREV DISCUSSION /321 PM MST/...Mostly dry weather with near average early July temperatures will persist through the 7 day forecast period. A trough moving through the Pacific Northwest will bring elevated southwest winds to the area Wednesday. Wind speeds will be slightly higher Wednesday than today, with gusts approaching 35 mph mainly from Flagstaff north. These increased winds combined with low afternoon humidity will cause near critical fire weather conditions generally from the I-40 corridor north. Dry west to southwest flow continues through the week with the only chance for afternoon thunderstorms over the White Mountains where enough moisture creeps in from the south. The active pattern continues to our north as an unseasonably cold low pressure system moves through the northwestern U.S. For Arizona, this will continue to bring dry and breezy weather with perhaps another notable increase in winds on Sunday. && .AVIATION...For the 06Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will redevelop aft 16Z Wed and then dcrs aft sun set Wed evening. Wind gusts of 30-35 kts expected Wed afternoon thru early evening before sunset. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A mostly dry west to southwest flow will continue. The only chance for afternoon thunderstorms will be over the White Mountains region Thursday. An increase in southwest winds combined with low humidity on Wednesday will result in near critical fire weather conditions generally from Flagstaff north. .Friday through Sunday...A chance for afternoon thunderstorms will continue across the White Mountains. Otherwise, dry weather with breezy afternoons and near average temperatures can be expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...TC/MCS AVIATION...TC FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Flagstaff AZ 1012 PM MST TUE JUL 5 2016 .SYNOPSIS...West to southwest flow across the region will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains and portions of northern Gila county Thursday through Saturday. && .DISCUSSION...Winds have dropped off this evening, and updates were made to reduce the winds. Cloud cover was also reduced for the overnight time period. Breezy to windy conditions develop on Wednesday as a trough goes by to the north. Near critical fire weather conditions will be possible along and west northwest of a line from Prescott to Winslow to Kayenta. && .PREV DISCUSSION /321 PM MST/...Mostly dry weather with near average early July temperatures will persist through the 7 day forecast period. A trough moving through the Pacific Northwest will bring elevated southwest winds to the area Wednesday. Wind speeds will be slightly higher Wednesday than today, with gusts approaching 35 mph mainly from Flagstaff north. These increased winds combined with low afternoon humidity will cause near critical fire weather conditions generally from the I-40 corridor north. Dry west to southwest flow continues through the week with the only chance for afternoon thunderstorms over the White Mountains where enough moisture creeps in from the south. The active pattern continues to our north as an unseasonably cold low pressure system moves through the northwestern U.S. For Arizona, this will continue to bring dry and breezy weather with perhaps another notable increase in winds on Sunday. && .AVIATION...For the 06Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will redevelop aft 16Z Wed and then dcrs aft sun set Wed evening. Wind gusts of 30-35 kts expected Wed afternoon thru early evening before sunset. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A mostly dry west to southwest flow will continue. The only chance for afternoon thunderstorms will be over the White Mountains region Thursday. An increase in southwest winds combined with low humidity on Wednesday will result in near critical fire weather conditions generally from Flagstaff north. .Friday through Sunday...A chance for afternoon thunderstorms will continue across the White Mountains. Otherwise, dry weather with breezy afternoons and near average temperatures can be expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...TC/MCS AVIATION...TC FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Tucson AZ 845 PM MST TUE JUL 5 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions area-wide Monday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Still looking at a few showers and thunderstorms near the International Border around KDUG. Otherwise, skies were mostly clear late this evening. The current forecast calls for a little more thunderstorm activity tomorrow and the next few days. This looks reasonable based on the latest model solutions. Thus, no updates necessary this evening. && .AVIATION...VALID THRU 07/06Z. Somewhat greater coverage of -TSRA/-SHRA will then occur Wednesday afternoon, with isolated to scattered -TSRA/-SHRA mainly from KTUS vicinity east and south to the New Mexico/International borders. Mostly clear skies late tonight into Wednesday morning. Scattered to broken clouds at 10k-15k ft msl Wednesday afternoon. Surface wind Wednesday afternoon will generally be wly at 10-15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Isolated to scattered showers and thunderstorms will occur from Tucson eastward and southward Wednesday through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions will prevail area-wide Monday into Tuesday. Otherwise, 20-foot winds will generally be terrain driven at less than 15 mph into early next week. && .PREV DISCUSSION...Some increase in showers/tstms is expected Wednesday into Friday, with the favored period during the afternoon/evening hours. Have noted that the GFS continued to befairly more robust to markedly more robust regarding precip chances versus the NAM/ECMWF/CMC solutions. For this forecast package, made only minor adjustments to the inherited gridded data PoP fields.Thus, isolated to scattered showers/tstms from Tucson eastward/southward Wednesday thru Friday with dry conditions across western/central Pima County and south-central Pinal County. Have maintained a slight chance of showers/ tstms Saturday across the White Mountains and far southeastern sections. Thereafter, the GFS/ECMWF/CMC were nearly identical with depicting a closed upper low over the Pacific Northwest Sunday. A tighter mid- level gradient should translate into stronger wly flow aloft, and shunt deeper moisture well east of this forecast area. Although the upper flow will weaken considerably by next Tuesday as high pressure aloft builds over the area, dry conditions are expected to continue. Thus, have continued with precip-free conditions area-wide Sunday into next Tuesday. Expect only very minor daily temp changes, and high temps will generally be within a couple of degs or so of normal into early next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Phoenix AZ 835 PM MST TUE JUL 5 2016 .SYNOPSIS... A break in the Monsoon pattern will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona next week Wednesday and Thursday, storm chances will be limited to southeast Arizona. Otherwise, expect dry conditions with near, to slightly above, normal temperatures. && .DISCUSSION... Another very quiet evening across our cwa, with westerly flow all the way through the column keeping monsoon moisture and thunderstorms well off to our south, mainly over extreme se AZ and northern Mexico. The combination of clear skies and a dry airmass (the 00z PSR sounding showing a pwat of only 0.81 inch) allowed temperatures to rise to near or slightly above 110F at the warmer lower desert locations again this afternoon. Tonight`s low appear that they will be very close to last night`s, in the upper-70 to mid-80 range across the lower deserts. Given current trends, other than some slight adjustments to the hourly temp/dewpoint grids, inherited forecasts are still looking good, and no updates are planned. && .PREVIOUS DISCUSSION... Rest of today through Thursday... A weak disturbance moving across AZ is producing some altocumulus plus there is some leftover lower level moisture over the higher terrain of AZ which has led to some flat cumulus development. Too stable and too little moisture for our area to see storms today. Expect they will be confined near the New Mexico border. For Wednesday and Thursday, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the broad subtropical high pressure region covering the southern CONUS/Mexico/Caribbean. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Hurricane Blas will be a non-factor. There will be some modest cooling...down to near normal/avg readings. Friday through Tuesday... The westerlies strengthen over the western states late in the week suppressing the axis of high pressure to our south . In the process, dry advection overspreads the region. This dry pattern stays in place through Tuesday. A proviso is that the deep moisture never goes exceedingly far away and remains over northwest Mexico. Thus if the intrusion of the westerlies winds up not being that strong and if convection over Sonora is more robust,then we may have more moisture to work with than anticipated. However, this scenario is really more relevant for southeast AZ as opposed to our forecast area. An upside to the influence of the westerlies is that temperatures are not looking to get out of hand despite the dry air. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Strong high pressure aloft and weak sfc pressure gradients to keep skies mainly clear through the taf period. Winds to mainly follow typical diurnal trends, with gusty afternoon westerly breezes at the Phx area terminals, gusty southerly afternoon winds at KBLH, and stronger westerly sundowner winds at KIPL again Wed evening. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Dry and persistent southwesterly flow aloft will maintain seasonably hot high temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds with gusts of 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Percha/AJ AVIATION...Percha FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Tucson AZ 330 PM MST TUE JUL 5 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions area-wide Monday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Isolated showers and thunderstorms will occur mainly near the international border south-to-southeast of Tucson this evening. These showers/tstms will end by midnight followed by clear skies or mostly clear skies late tonight into Wednesday morning. Some increase in showers/tstms is expected Wednesday into Friday, with the favored period during the afternoon/evening hours. Have noted that the GFS continued to be fairly more robust to markedly more robust regarding precip chances versus the NAM/ECMWF/CMC solutions. For this forecast package, made only minor adjustments to the inherited gridded data PoP fields. Thus, isolated to scattered showers/tstms from Tucson eastward/southward Wednesday thru Friday with dry conditions across western/central Pima County and south- central Pinal County. Have maintained a slight chance of showers/ tstms Saturday across the White Mountains and far southeastern sections. Thereafter, the GFS/ECMWF/CMC were nearly identical with depicting a closed upper low over the Pacific Northwest Sunday. A tighter mid- level gradient should translate into stronger wly flow aloft, and shunt deeper moisture well east of this forecast area. Although the upper flow will weaken considerably by next Tuesday as high pressure aloft builds over the area, dry conditions are expected to continue. Thus, have continued with precip-free conditions area-wide Sunday into next Tuesday. Expect only very minor daily temp changes, and high temps will generally be within a couple of degs or so of normal into early next week. && .AVIATION...VALID THRU 07/00Z. Expect isolated -TSRA/-SHRA this evening mainly near the international border southeast of KTUS. The best chance of -TSRA/-SHRA will be near the KDUG terminal, and perhaps further west and northwest to KFHU and KALK. However, the probability of occurrence is too low to include in the TAFs. Somewhat greater coverage of -TSRA/-SHRA will then occur Wednesday afternoon, with isolated to scattered -TSRA/-SHRA mainly from KTUS vicinity east and south to the New Mexico/International borders. Otherwise, west to northwest of KTUS expect clear skies to scattered clouds above 20k ft msl thru the period. KTUS vicinity east-to-south, a few to scattered clouds at 10k-15k ft msl into this evening followed by decreasing clouds with mostly clear skies late tonight into Wednesday morning. Scattered to broken clouds at 10k-15k ft msl Wednesday afternoon. Surface wind this evening and Wednesday afternoon will generally be wly at 10-15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Isolated to scattered showers and thunderstorms will occur from Tucson eastward and southward Wednesday through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions will prevail area-wide Monday into Tuesday. Otherwise, 20-foot winds will generally be terrain driven at less than 15 mph into early next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson Francis
Area Forecast Discussion National Weather Service Flagstaff AZ 321 PM MST TUE JUL 5 2016 .SYNOPSIS...West to southwest flow across the region will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains. && .DISCUSSION...Mostly dry weather with near average early July temperatures will persist through the 7 day forecast period. A trough moving through the Pacific Northwest will bring elevated southwest winds to the area Wednesday. Wind speeds will be slightly higher Wednesday than today, with gusts approaching 35 mph mainly from Flagstaff north. These increased winds combined with low afternoon humidity will cause near critical fire weather conditions generally from the I-40 corridor north. Dry west to southwest flow continues through the week with the only chance for afternoon thunderstorms over the White Mountains where enough moisture creeps in from the south. The active pattern continues to our north as an unseasonably cold low pressure system moves through the northwestern U.S. For Arizona, this will continue to bring dry and breezy weather with perhaps another notable increase in winds on Sunday. && .AVIATION...For the 00Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will diminish after sunset tonight and redevelop aft 16Z Wed. Wind gusts of 30-35 kts expected Wed afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A mostly dry west to southwest flow will continue. The only chance for afternoon thunderstorms will be over the White Mountains region Thursday. An increase in southwest winds combined with low humidity on Wednesday will result in near critical fire weather conditions generally from Flagstaff north. .Friday through Sunday...A chance for afternoon thunderstorms will continue across the White Mountains. Otherwise, dry weather with breezy afternoons and near average temperatures can be expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MCS AVIATION...MCS FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Phoenix AZ 249 PM MST TUE JUL 5 2016 .SYNOPSIS... A break in the Monsoon pattern will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona next week Wednesday and Thursday, storm chances will be limited to southeast Arizona. Otherwise, expect dry conditions with near, to slightly above, normal temperatures. && .DISCUSSION... Rest of today through Thursday... A weak disturbance moving across AZ is producing some altocumulus plus there is some leftover lower level moisture over the higher terrain of AZ which has led to some flat cumulus development. Too stable and too little moisture for our area to see storms today. Expect they will be confined near the New Mexico border. For Wednesday and Thursday, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the broad subtropical high pressure region covering the southern CONUS/Mexico/Caribbean. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Hurricane Blas will be a non-factor. There will be some modest cooling...down to near normal/avg readings. Friday through Tuesday... The westerlies strengthen over the western states late in the week suppressing the axis of high pressure to our south . In the process, dry advection overspreads the region. This dry pattern stays in place through Tuesday. A proviso is that the deep moisture never goes exceedingly far away and remains over northwest Mexico. Thus if the intrusion of the westerlies winds up not being that strong and if convection over Sonora is more robust,then we may have more moisture to work with than anticipated. However, this scenario is really more relevant for southeast AZ as opposed to our forecast area. An upside to the influence of the westerlies is that temperatures are not looking to get out of hand despite the dry air. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Winds will favor a normal diurnal sequence with occasional wind gusts of 15 to 20 kts. through the early evening--although more frequent wind gusts are likely for the southeast California terminals. Otherwise skies will remain mostly clear with few to sct mid and high clouds throughout the period. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Dry and persistent southwesterly flow aloft will maintain seasonably hot high temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds with gusts of 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...AJ AVIATION...Sawtelle FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Flagstaff AZ Issued by National Weather Service Las Vegas NV 911 AM MST TUE JUL 5 2016 .SYNOPSIS...Westerly flow across the southwest will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains. && .UPDATE...Overall the forecast is in good shape, with no updates planned this morning. Dry southwest flow remains in control with breezes expected each afternoon. && .PREV DISCUSSION /349 AM MST/...A drying west-southwesterly flow will persist over the next several days across northern Arizona. This will lead to fair and generally dry, but somewhat breezy, weather for much of the coming week. Near normal temperatures are also anticipated. While intermittent pushes of moisture may produce a slight chance for thunderstorms over far eastern Arizona, the pattern looks typical for an extended monsoonal break through the 7- day forecast. && .AVIATION...For the 18Z Package...Expect VFR conditions over the next 24 hrs, with breezy south to southwest winds each afternoon. A slight chance of an afternoon -SHRA/-TSRA over the White Mtns southeast of KSOW remains possible. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A drier southwesterly flow regime will limit any chance for a shower or storm to the White Mountains through Wednesday. Breezy afternoon winds will develop, with the highest wind speeds Wednesday as a trough passes north of the state. Thursday through Saturday...A chance for afternoon thunderstorms exists each day across the White Mountains. Elsewhere...dry weather with breezy afternoons expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...NWS Las Vegas PUBLIC...KD AVIATION...JJ FIRE WEATHER...JJ For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Phoenix AZ 904 AM MST TUE JUL 5 2016 .SYNOPSIS... Unseasonably dry air will continue to filter into the region as the pattern will transition away from a typical summer monsoon appearance. Temperatures will remain in a near normal range throughout the week under mostly clear skies. Only a modest chance of showers will exist through southeast and eastern Arizona during the midweek period, with virtually no chance of rain at lower elevations from central Arizona through southern California. && .DISCUSSION... Some of the larger circulation features over western North America and northeast Pacific include troughing centered over the Canadian Rockies (extending well into the NW CONUS), a large anticyclone west of the trough, and a very broad region of high pressure with an axis extending from west of Baja Mexico to east of Florida (containing multiple anticyclonic circulations). With troughing to the northwest and the axis of high pressure just to the south, our forecast area is largely within southwesterly flow aloft. There is a weak disturbance within that southwesterly flow which is producing some altocumulus. However, the 12Z soundings show that this disturbance will not be able to do much of anything else given how warm aloft we are and the drying that has taken place in the lower levels. Thus, we will have another very warm day with storm activity limited to areas well outside of our territory (near the New Mexico border). For Wed and Thu, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the high pressure region over/near us. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Made some subtle upward adjustments to the temperatures for today otherwise, forecasts in good shape. && .PREVIOUS DISCUSSION...Issued 145 am MST/PDT High pressure remains situated over northern Chihuahua early this morning while several shortwaves continue to carve out longwave troughing over the Pacific Northwest. This pattern configuration will only reinforce southwest/westerly flow throughout the SW Conus with an overall anti- cyclonic subsident regime. Boundary layer moisture also continues to be eroded with 00Z KPSR sounding data sampling an anemic 6 g/kg sfc-H7 mixing ratio, while KTWC data was only slightly more supportive for convective development at 8 g/kg. However, unusually warm temperatures aloft have been amplifying with H5 readings spiking at -4C and falling near the climatological 90th percentile capping any deep convection. This general pattern will essentially hold for the entire week keeping all but the southeast portions of Arizona devoid of thunderstorms (much less for all but afternoon fair weather mountain cumulus). The operational GFS still maintains a forecast of more robust Sonoran outflow advecting marginally better moisture profiles northward towards Pinal and Gila counties Wednesday and Thursday. However, trends in this operational run have definitely been towards a lower magnitude and less influential moisture push with only 8 g/kg materializing in the sfc-H7 layer. Thus, other than a brief shower/virga over far southeast Gila County, saw no justifiable reason to include any pops through the remainder of the forecast area into the weekend. One positive of this scenario is unlike most mid-monsoon season pattern breakdowns, this convectively inactive period will feature H5 heights depressed near 592dm and afternoon H8 temperatures only hovering between +25C and +29C. Typically, breaks in thunderstorm activity in July would result in near record highs, but model output emphatically supports temperatures near to only slightly above average throughout the week. In fact, spread among all post processed raw and numerical guidance persists in an extremely narrow range yielding excellent forecast confidence. Convection will continue to remain thoroughly absent from the forecast area well into next week as larger negative height anomalies develop over the Pacific Northwest. This will exacerbate westerly flow through the intermountain west and SW Conus further eliminating any sense of quality boundary layer moisture across the forecast area. There is strong evidence that sfc dewpoints through the weekend and into early next week fall into the 30s with total column Pwats descending towards 0.50 inches (climatologically near the 10th percentile for early/mid July). Thus, instead of entering deeper into monsoon flow of mid July, the atmosphere is actually regressing more towards an early June dry pattern. Though ensemble spread begins to grow towards the middle of next week, it may very well be until the end of next week at the earliest before sufficient moisture can return north and storm chances reenter the forecast picture. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Dry westerly flow aloft with only few to sct high clouds at all area terminals. Winds to mainly follow typical diurnal trends, with some afternoon gustiness likely, especially at KBLH. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Thursday through Monday: Dry southwesterly flow aloft will be in place through early next week. Minimum humidity values will be at or below 10% at most lower desert locations. Overnight recovery will be only fair. Surface winds will favor south-southwesterly in the afternoon and evening with gusts in the teens. Overall, the pattern is more characteristic of June rather than July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...AJ PREVIOUS DISCUSSION...MO AVIATION...Kuhlman FIRE WEATHER...AJ
Area Forecast Discussion National Weather Service Tucson AZ 900 AM MST TUE JUL 5 2016 .SYNOPSIS...A relatively dry air mass with westerly flow aloft will continue to limit thunderstorm coverage today. More moisture will increase thunderstorm chances the second half of the week. Another drier and warmer pattern moves in for next weekend. && .DISCUSSION...IR/Visible satellite imagery and surface observations depicted clear skies across much of southeast Arizona at this time. A few mid-level clouds were noted northwest of Tucson in the vicinity of Picacho Peak, and near the International border adjacent Cochise County. Dewpoints at lower elevations valid 15Z ranged from the 50s-lower 60s, and these temps were nearly identical to 24 hours ago. Surface temps valid 15Z were also essentially unchanged versus this time Monday. 05/12Z KTWC sounding total precip water value of 1.11 inches increased only 0.04 inch versus 24 hours ago. The column was nearly saturated around 600 mb but was quite dry in the surface-700 mb layer and above 500 mb. 05/12Z upper air plots depicted a 500 mb ridge axis that extended from west of northern Baja California eastward to Florida. Meanwhile, a belt of westerlies encompassed the northern CONUS with a 559 dm low centered over British Columbia. Light wly/swly flow aloft prevailed across southeast Arizona. The 12Z Univ. of AZ WRF-NAM was similar to the HRRR in depicting the initial development for showers/tstms late this morning or early this afternoon to occur near the Chiricahua Mountains in eastern Cochise County, or perhaps further west near the Huachuca Mountains in southwestern Cochise County. The bulk of showers/tstms later this afternoon and evening is progged to occur generally across the New Mexico bootheel, but some precip echoes were progged to be further west into about the southeast one quarter of Cochise County. Based on these solutions, see no reason to tamper with the official forecast that depicts isolated showers/tstms this afternoon/evening to occur from near Nogales eastward to the Chiricahua Mountains, or generally near the International border adjacent eastern Santa Cruz/ Cochise Counties. Dry conditions will prevail elsewhere, with high temps this afternoon virtually identical to temps achieved Monday afternoon. Please refer to the additional sections for further detail. && .AVIATION...VALID THRU 06/18Z. Expect isolated -TSRA/-SHRA this afternoon and evening mainly near the International border southeast of KTUS. The best chance of -TSRA/-SHRA will be near the KDUG terminal, and perhaps further west and northwest to KFHU and KALK. However, the probability of occurrence is too low to include in the TAFs. Otherwise, west to northwest of KTUS expect clear skies to scattered clouds above 20k ft msl thru the period. KTUS vicinity east-to-south few to scattered clouds at 10k-15k ft msl into this evening followed by decreasing clouds with mostly clear skies late tonight into early Wednesday morning. Surface wind this afternoon will generally be wly at 10-15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Enough moisture will linger for thunderstorms near the International border again today, with dry conditions elsewhere. Another brief push of moisture will bring increased coverage of showers and thunderstorms from near Tucson south and east Wednesday into Friday. Drying will then occur once again this weekend. 20-ft winds will generally favor diurnal patterns at 15 mph or less, with some enhancement in areas where afternoon westerly/northwesterly flow is the norm. && .PREV DISCUSSION /150 AM MST/...Water vapor imagery and 05/00Z upper- air plots show a sprawling ridge that extends generally west to east from the central Baja Peninsula across northern Mexico and into west Texas. This has resulted in a continuation of a dry westerly flow aloft across the desert southwest as evidenced on the 05/00Z KTWC sounding. The PW on the sounding was up a bit from 12 to 24 hours ago, with a value of 1.28 inches, which was about two-tenths of an inch greater. Both the CIRA LPW Total and the U of A GPS PW show a value as of 06Z of just a tad over an inch. Models indicate that the ridge to our south will shift eastward through early Wednesday to a position over the southern plains with the ridge axis extending westward across northern Mexico. As this shift occurs, return flow on the western flank of the ridge will allow moisture to increase during the middle to latter part of the week. Therefore, expect thunderstorm chances to increase mainly Wednesday into Thursday, with the focus for thunderstorms being from around Nogales to Douglas, with the activity spreading a bit farther north Thursday. For now it looks like the farthest northwestern extent of the storms will be around the Tucson area, with very little threat west and north of the city. Even so, it only looks like isolated coverage for the Tucson metro. However, this could change depending on what subsequent model runs indicate, so stay tuned. Confidence is not high at this point with the GFS being the most robust model in wanting to bring in the threat for storms, whereas the NAM and ECMWF, not so much. Just one example, looking at MOS POP numbers for Tucson, the NAM shows POPS in the single digits for Wednesday through Thursday, whereas the GFS has 12-hour POPS of 14, 39 and 21 percent for Wednesday, Wednesday night and Thursday, respectively. ECMWF is much closer to the NAM numbers. So, sorta went with a blend, but not yet close to the GFS values, especially for Wednesday night. With subsequent model runs, the forecast may change between now and the middle to latter part of the week. Confidence is moderate to high at this point that areas along the international border will see at least scattered convection. By the weekend a low pressure system will begin to affect the Pacific northwest as the ridge becomes reestablished to our south again, resulting in a drying trend for the weekend and into early next week. For Tucson, high temperatures will range from 2 to 4 degs above normal today and then near normal Wednesday through Friday before becoming around 2 to 4 degs above normal again for the weekend and early next week. Low temps will range from 4 to 6 degs above normal Wednesday morning, then around 2 to 4 degs above normal thereafter. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson DISCUSSION...Francis PREVIOUS DISCUSSION...Mollere AVIATION/FIRE WEATHER...French
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1146 PM CDT TUE JUL 5 2016 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Wednesday) Issued at 332 PM CDT TUE JUL 5 2016 Late this afternoon temperatures were in the late 90s with dewpoints int he the mid to upper 70s across east central KS, which has caused heat indices to be in the 110 to 114 degree range. The mixing was a bit deeper across the western counties where dewpoints have dropped into the upper 60s to lower 70s. Most numerical models do not show thunderstorms developing across the CWA this afternoon and evening, though MLCAPE values range from 4,000 to 5,000 J/KG. The HRRR is the only model that shows isolated thunderstorms developing across the CWA late this afternoon and evening but based on the lack of vertical CU development, I really do not see any boundary or minor vortmaxes that could help increase ascent for any thunderstorm development late this afternoon. Tonight, most models show scattered thunderstorms across northeast CO and the southern NE Panhandle this afternoon congealing into an MCS which will track east or southeast across the plains. The HRRR, NAM, and WRF solutions show the MCS tracking southeast across the CWA, though it may begin to weaken as it moves into northeast and east central KS late Tonight. If an MCS develops and maintains its intensity through the night then there will be a chance for heavy rainfall and potential damaging wind gusts along with penny to quarter size hail, with the better chance for strong to severe thunderstorms across north central KS during the early morning hours Wednesday. The exact track and the intensity of the MCS will not be known until it develops and begins to propagate to the southeast. Therefore, I went with chance pops after 6Z across the CWA but there will be higher pops wherever the MCS tracks. Wednesday, The morning thunderstorm complex will exit the eastern counties of the CWA by 15Z. Skies should clear from west to east across the CWA during the late morning and early afternoon hours. Highs should warm into the lower and mid 90s across the southern counties along with dewpoints holding in the mid 70s. If the MCS remains intense through the morning hours, then an outflow boundary may shift south of the CWA and the cloud cover may hold through most of the afternoon hours keeping Highs several degrees cooler. At this time I think we will clear out by afternoon and heat up into the mid 90s south of I-70. Therefore I have issued a heat advisory for areas along and south of I-70 from 12 Noon through 8 PM Wednesday where heat indices around 105 degrees during the afternoon hours. .LONG TERM...(Wednesday Night through Tuesday) Issued at 332 PM CDT TUE JUL 5 2016 Wednesday Night through Friday... Storms are expected to form in NW Kansas and SW Nebraska Wednesday evening and move east toward the area overnight. There is a chance some storms may make it into the northern portion of the CWA by late evening so low end PoPs are included during this time frame mainly north of I-70. Thunderstorm chances continue for Thursday as another shortwave is forecast to move through late afternoon into the evening. Soundings indicate a cap will be in place most of the afternoon Thursday, but with a front in the area and sufficient heating, the cap should degrade allowing a chance for storms to form. Models show high CAPE values over 3000 J/kg along with 0-6 km shear ranging between 25-35 knots. This makes organized convection possible with strong winds and gusty hail being the main hazard. Friday looks to have the best chance to be dry, although another shortwave near central Kansas may provide some focus for storms in east central Kansas during the afternoon Friday. As for temperatures during this time, the hottest day looks to be Thursday with heat indicies once again near 105 degrees due to dewpoints in the low 70s Thursday afternoon. The front finally makes it through the area this day allowing Friday to cool slightly with highs in the low 90s. Friday Night through Tuesday... Weak mid-level ridging will be in place at the beginning of the period. A frontal boundary is expected to stall in southern Kansas Saturday afternoon. This may be the focal point for thunderstorm development Saturday afternoon and evening. An amplified trough will be in place across the Western US late next weekend. EC and GFS differ on the effects from the trough. GFS much more bullish with strength of a shortwave trough lifting out from base of the trough. The unsettled pattern will continue through the remainder of the period as a potentially unstable atmosphere will be in place. As mid- level southwesterly flow settles in across the area, weak embedded waves will have the potential to spark thunderstorm activity for the remainder of the period. Temperatures will remain fairly seasonal with high temperatures in the upper 80s to lower 90s. With dew points near 70 degrees, heat index values will range from the mid- 90s to near 100 degrees for the entire extended period. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday Night) Issued at 1146 PM CDT TUE JUL 5 2016 Have narrowed down VCTS a bit, with some uncertainty remaining on coverage and timing even in the next few hours. Wind shear continues to look to weak and short lived for a mention. VFR conditions otherwise anticipated. && .TOP Watches/Warnings/Advisories... Heat Advisory from 1 PM to 8 PM CDT Wednesday for KSZ034>039- 054>056-058-059. && $$ SHORT TERM...Gargan LONG TERM...Heller/Baerg AVIATION...65 Area Forecast Discussion National Weather Service Flagstaff AZ 859 AM MST WED JUL 6 2016 .SYNOPSIS...A low pressure trough anchored along the west coast will bring dry southwesterly winds into Arizona through next week. The only exception will be low chances for a few thunderstorms in the White Mountains region through Saturday. There remains a fair chance this dry spell may last through the first half of July. && .DISCUSSION...June weather ahead. What is known as a fair weather pattern is upon us. Gusty winds will lead to elevated fire weather concerns. Otherwise, many of us impatiently wait for the return of the monsoon. A long wave trough anchored along the west coast will keep the subtropical ridge pinned down over northern Mexico. The position of the trough/ridge couplet will keep Arizona locked into a long term dry southwesterly flow pattern into next week. The only exception to this extended dry spell will be slight chances for thunderstorms across the White Mountains region each day through Saturday. Our confidence in this dry pattern remains high into the first half of next week. There is a fair chance this dry break in the otherwise wet Monsoon pattern will last through at least mid July. Surface winds will become breezy as short wave troughs move through the long wave pattern increasing the pressure gradient. A few days this week may approach critical fire weather thresholds with very dry humidity levels and stronger wind speeds. && .AVIATION...For the 18Z package...VFR conditions will continue over the next 24 hours. A weak weather system will bring southwest winds of 10-25 kts gusting 35 kts into the early evening. Light winds overnight with another round of locally gusty winds set for Thursday. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...An increase in southwest winds combined with low humidity this afternoon will result in near critical fire weather conditions from Flagstaff north and west. There will be a slight chance for afternoon and evening high based thunderstorms over portions of the White Mountains Thursday afternoon. .Friday through Sunday...Near average temperatures and mostly dry conditions are forecast through the period, except for a slight chance of afternoon thunderstorms over portions of the White Mountains. Near critical fire weather conditions are possible Sunday afternoon. $$ PUBLIC...McCollum/TC AVIATION...McCollum/TC FIRE WEATHER...TC For Northern Arizona weather information visit weather.gov/flagstaff
  [top] Area Forecast Discussion National Weather Service Phoenix AZ 854 AM MST WED JUL 6 2016 .UPDATE... && .SYNOPSIS... A break in thunderstorm activity with near average temperatures will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona today and Thursday, thunderstorm chances will be limited to southeast Arizona. Unusually quiet weather may persist through all of next week before any storms can move north once again. && .DISCUSSION... Clear skies are over the forecast office region although we are starting to see some moisture and clouds pushing into far southeast Arizona. In fact, dew points are significantly higher...especially along the Colorado River valley and southwest Arizona. This was not well represented in the models and so reflects a bit of a change for the short-term outlook. Primarily for the lower deserts this means there is a chance for some low-end monsoon activity for areas such as southern Gila County and parts of Pinal County this afternoon. This would primarily be in the form outflow activities such as blowing dust and maybe a few showers. Accordingly will make slight tweak to the PoPs for this afternoon and may have to take another look at tomorrow as well. && .PREVIOUS DISCUSSION... A thunderstorm complex over central Sonora associated with a weak inverted trough has largely dissipated early this evening, however has essentially bifurcated ridging aloft with one high pressure center shifting into west Texas while a western branch remains situated over far SE Arizona. Deep westerly flow throughout the vast majority of Arizona over the past 48 hours has progressively eroded moisture with both 00Z KPSR and KTWC sounding data sampling only 5 g/kg within the boundary layer and total column pwats falling near 0.75 inches. However, the degenerated Sonoran convective complex has created a pool of more substantial moisture which will partially bleed north across the international border in weak southwest flow today and Thursday. The first signs of this moisture intrusion can be seen in overnight KOLS observations with enhanced south winds and sfc dewpoints jumping over 60F. Forecast BUFR soundings resoundingly show some of this shallow moisture advecting north into the Phoenix area later this morning, and eventually deeper 8-9 g/kg sfc-H7 profiles enveloping much of the eastern third of the forecast area this afternoon. However, temperatures in the H7-H5 layer remain unseasonably warm under a general anti-cyclonic subsident flow regime leaving minimal instability and notable Cinh. While a stray shower could conceivably clip through higher terrain areas of southern Gila county, ensemble probabilities barely breach single digits through Thursday before dropping off completely heading into the weekend. The most notable weather feature locally through the weekend and into early next week is actually the complete lack of weather and thunderstorm activity. Deep negative height anomalies (around 2 normalized standard deviations below average) will propagate from the Pacific NW into the Great Basin with intense jet energy punching over the Sierra chain towards the central Rockies. Essentially every NAEFS member shows this scenario where the mid and upper tropospheric u-wind component becomes anomalously strong and within a climatologically rare threshold for mid July. Unlike much of the summer season, forecast confidence is exceedingly high and so much so as to assign absolutely no chance of rainfall for the entire Sat- Wed time frame as aggressive drying spreads through the atmospheric column. Furthermore with this increased westerly flow and depressed troughing pattern, H5 heights will languish only around 590dm yielding temperatures very close to the seasonal climatology. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: The persistent dry westerly flow aloft continues, but a brief resurgence of low level moisture will make its way northward into southeast Arizona today. However, any thunderstorm activity today will stay well to our southeast with only minimal chance of any cirrus blowoff this evening. Winds to mainly follow typical diurnal trends, with gusty afternoon westerly breezes at the Phx area terminals, gusty southerly afternoon winds at KBLH, and stronger westerly sundowner winds at KIPL again Wed evening. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Friday through Tuesday: Dry and persistent southwesterly flow will maintain seasonable temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds peaking at 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Waters/MO AVIATION...Kuhlman FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Phoenix AZ 513 AM MST WED JUL 6 2016 .UPDATE...Updated Aviation Discussion... && .SYNOPSIS... A break in thunderstorm activity with near average temperatures will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona today and Thursday, thunderstorm chances will be limited to southeast Arizona. Unusually quiet weather may persist through all of next week before any storms can move north once again. && .DISCUSSION... A thunderstorm complex over central Sonora associated with a weak inverted trough has largely dissipated early this evening, however has essentially bifurcated ridging aloft with one high pressure center shifting into west Texas while a western branch remains situated over far SE Arizona. Deep westerly flow throughout the vast majority of Arizona over the past 48 hours has progressively eroded moisture with both 00Z KPSR and KTWC sounding data sampling only 5 g/kg within the boundary layer and total column pwats falling near 0.75 inches. However, the degenerated Sonoran convective complex has created a pool of more substantial moisture which will partially bleed north across the international border in weak southwest flow today and Thursday. The first signs of this moisture intrusion can be seen in overnight KOLS observations with enhanced south winds and sfc dewpoints jumping over 60F. Forecast BUFR soundings resoundingly show some of this shallow moisture advecting north into the Phoenix area later this morning, and eventually deeper 8-9 g/kg sfc-H7 profiles enveloping much of the eastern third of the forecast area this afternoon. However, temperatures in the H7-H5 layer remain unseasonably warm under a general anti-cyclonic subsident flow regime leaving minimal instability and notable Cinh. While a stray shower could conceivably clip through higher terrain areas of southern Gila county, ensemble probabilities barely breach single digits through Thursday before dropping off completely heading into the weekend. The most notable weather feature locally through the weekend and into early next week is actually the complete lack of weather and thunderstorm activity. Deep negative height anomalies (around 2 normalized standard deviations below average) will propagate from the Pacific NW into the Great Basin with intense jet energy punching over the Sierra chain towards the central Rockies. Essentially every NAEFS member shows this scenario where the mid and upper tropospheric u-wind component becomes anomalously strong and within a climatologically rare threshold for mid July. Unlike much of the summer season, forecast confidence is exceedingly high and so much so as to assign absolutely no chance of rainfall for the entire Sat- Wed time frame as aggressive drying spreads through the atmospheric column. Furthermore with this increased westerly flow and depressed troughing pattern, H5 heights will languish only around 590dm yielding temperatures very close to the seasonal climatology. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: The persistent dry westerly flow aloft continues, but a brief resurgence of low level moisture will make its way northward into southeast Arizona today. However, any thunderstorm activity today will stay well to our southeast with only minimal chance of any cirrus blowoff this evening. Winds to mainly follow typical diurnal trends, with gusty afternoon westerly breezes at the Phx area terminals, gusty southerly afternoon winds at KBLH, and stronger westerly sundowner winds at KIPL again Wed evening. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Friday through Tuesday: Dry and persistent southwesterly flow will maintain seasonable temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds peaking at 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...MO AVIATION...Kuhlman FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Phoenix AZ 513 AM MST WED JUL 6 2016 .UPDATE...Updated Aviation Discussion... && .SYNOPSIS... A break in thunderstorm activity with near average temperatures will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona today and Thursday, thunderstorm chances will be limited to southeast Arizona. Unusually quiet weather may persist through all of next week before any storms can move north once again. && .DISCUSSION... A thunderstorm complex over central Sonora associated with a weak inverted trough has largely dissipated early this evening, however has essentially bifurcated ridging aloft with one high pressure center shifting into west Texas while a western branch remains situated over far SE Arizona. Deep westerly flow throughout the vast majority of Arizona over the past 48 hours has progressively eroded moisture with both 00Z KPSR and KTWC sounding data sampling only 5 g/kg within the boundary layer and total column pwats falling near 0.75 inches. However, the degenerated Sonoran convective complex has created a pool of more substantial moisture which will partially bleed north across the international border in weak southwest flow today and Thursday. The first signs of this moisture intrusion can be seen in overnight KOLS observations with enhanced south winds and sfc dewpoints jumping over 60F. Forecast BUFR soundings resoundingly show some of this shallow moisture advecting north into the Phoenix area later this morning, and eventually deeper 8-9 g/kg sfc-H7 profiles enveloping much of the eastern third of the forecast area this afternoon. However, temperatures in the H7-H5 layer remain unseasonably warm under a general anti-cyclonic subsident flow regime leaving minimal instability and notable Cinh. While a stray shower could conceivably clip through higher terrain areas of southern Gila county, ensemble probabilities barely breach single digits through Thursday before dropping off completely heading into the weekend. The most notable weather feature locally through the weekend and into early next week is actually the complete lack of weather and thunderstorm activity. Deep negative height anomalies (around 2 normalized standard deviations below average) will propagate from the Pacific NW into the Great Basin with intense jet energy punching over the Sierra chain towards the central Rockies. Essentially every NAEFS member shows this scenario where the mid and upper tropospheric u-wind component becomes anomalously strong and within a climatologically rare threshold for mid July. Unlike much of the summer season, forecast confidence is exceedingly high and so much so as to assign absolutely no chance of rainfall for the entire Sat- Wed time frame as aggressive drying spreads through the atmospheric column. Furthermore with this increased westerly flow and depressed troughing pattern, H5 heights will languish only around 590dm yielding temperatures very close to the seasonal climatology. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: The persistent dry westerly flow aloft continues, but a brief resurgence of low level moisture will make its way northward into southeast Arizona today. However, any thunderstorm activity today will stay well to our southeast with only minimal chance of any cirrus blowoff this evening. Winds to mainly follow typical diurnal trends, with gusty afternoon westerly breezes at the Phx area terminals, gusty southerly afternoon winds at KBLH, and stronger westerly sundowner winds at KIPL again Wed evening. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Friday through Tuesday: Dry and persistent southwesterly flow will maintain seasonable temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds peaking at 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...MO AVIATION...Kuhlman FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Flagstaff AZ 354 AM MST WED JUL 6 2016 .SYNOPSIS...A low pressure trough anchored along the west coast will bring dry southwesterly winds into Arizona through next week. The only exception will be low chances for a few thunderstorms in the White Mountains region through Saturday. There remains a fair chance this dry spell may last through the first half of July. && .DISCUSSION...A long wave trough anchored along the west coast will keep the subtropical ridge pinned down over northern Mexico. The position of the trough ridge couplet will keep Arizona locked into a long term dry southwesterly flow pattern into next week. The only exception to this extended dry spell will be slight chances for thunderstorms across the White Mountains region each day through Saturday. Our confidence in this dry pattern remains high into the first half of next week. There is a fair chance this dry break in the otherwise wet Monsoon pattern will last through at least mid July. Surface winds will become breezy as short wave troughs move through the long wave pattern increasing the pressure gradient. A few days this week may approach critical fire weather thresholds with very dry humidity levels and stronger wind speeds. && .AVIATION...For the 12Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will develop aft 15Z Wed and then dcrs aft sun set Wed evening. Wind gusts of 30-35 kts expected Wed afternoon thru early evening before sunset. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...An increase in southwest winds combined with low humidity this afternoon will result in near critical fire weather conditions from Flagstaff north and west. There will be a slight chance for afternoon and evening high based thunderstorms over portions of the White Mountains Thursday afternoon. .Friday through Sunday...Near average temperatures and mostly dry conditions are forecast through the period, except for a slight chance of afternoon thunderstorms over portions of the White Mountains. Near critical fire weather conditions are possible Sunday afternoon. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...Bohlin AVIATION...TC FIRE WEATHER...TC For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Flagstaff AZ 354 AM MST WED JUL 6 2016 .SYNOPSIS...A low pressure trough anchored along the west coast will bring dry southwesterly winds into Arizona through next week. The only exception will be low chances for a few thunderstorms in the White Mountains region through Saturday. There remains a fair chance this dry spell may last through the first half of July. && .DISCUSSION...A long wave trough anchored along the west coast will keep the subtropical ridge pinned down over northern Mexico. The position of the trough ridge couplet will keep Arizona locked into a long term dry southwesterly flow pattern into next week. The only exception to this extended dry spell will be slight chances for thunderstorms across the White Mountains region each day through Saturday. Our confidence in this dry pattern remains high into the first half of next week. There is a fair chance this dry break in the otherwise wet Monsoon pattern will last through at least mid July. Surface winds will become breezy as short wave troughs move through the long wave pattern increasing the pressure gradient. A few days this week may approach critical fire weather thresholds with very dry humidity levels and stronger wind speeds. && .AVIATION...For the 12Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will develop aft 15Z Wed and then dcrs aft sun set Wed evening. Wind gusts of 30-35 kts expected Wed afternoon thru early evening before sunset. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...An increase in southwest winds combined with low humidity this afternoon will result in near critical fire weather conditions from Flagstaff north and west. There will be a slight chance for afternoon and evening high based thunderstorms over portions of the White Mountains Thursday afternoon. .Friday through Sunday...Near average temperatures and mostly dry conditions are forecast through the period, except for a slight chance of afternoon thunderstorms over portions of the White Mountains. Near critical fire weather conditions are possible Sunday afternoon. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...Bohlin AVIATION...TC FIRE WEATHER...TC For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Phoenix AZ 150 AM MST WED JUL 6 2016 .SYNOPSIS... A break in thunderstorm activity with near average temperatures will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona today and Thursday, thunderstorm chances will be limited to southeast Arizona. Unusually quiet weather may persist through all of next week before any storms can move north once again. && .DISCUSSION... A thunderstorm complex over central Sonora associated with a weak inverted trough has largely dissipated early this evening, however has essentially bifurcated ridging aloft with one high pressure center shifting into west Texas while a western branch remains situated over far SE Arizona. Deep westerly flow throughout the vast majority of Arizona over the past 48 hours has progressively eroded moisture with both 00Z KPSR and KTWC sounding data sampling only 5 g/kg within the boundary layer and total column pwats falling near 0.75 inches. However, the degenerated Sonoran convective complex has created a pool of more substantial moisture which will partially bleed north across the international border in weak southwest flow today and Thursday. The first signs of this moisture intrusion can be seen in overnight KOLS observations with enhanced south winds and sfc dewpoints jumping over 60F. Forecast BUFR soundings resoundingly show some of this shallow moisture advecting north into the Phoenix area later this morning, and eventually deeper 8-9 g/kg sfc-H7 profiles enveloping much of the eastern third of the forecast area this afternoon. However, temperatures in the H7-H5 layer remain unseasonably warm under a general anti-cyclonic subsident flow regime leaving minimal instability and notable Cinh. While a stray shower could conceivably clip through higher terrain areas of southern Gila county, ensemble probabilities barely breach single digits through Thursday before dropping off completely heading into the weekend. The most notable weather feature locally through the weekend and into early next week is actually the complete lack of weather and thunderstorm activity. Deep negative height anomalies (around 2 normalized standard deviations below average) will propagate from the Pacific NW into the Great Basin with intense jet energy punching over the Sierra chain towards the central Rockies. Essentially every NAEFS member shows this scenario where the mid and upper tropospheric u-wind component becomes anomalously strong and within a climatologically rare threshold for mid July. Unlike much of the summer season, forecast confidence is exceedingly high and so much so as to assign absolutely no chance of rainfall for the entire Sat- Wed time frame as aggressive drying spreads through the atmospheric column. Furthermore with this increased westerly flow and depressed troughing pattern, H5 heights will languish only around 590dm yielding temperatures very close to the seasonal climatology. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Strong high pressure aloft and weak sfc pressure gradients to keep skies mainly clear through the taf period. Winds to mainly follow typical diurnal trends, with gusty afternoon westerly breezes at the Phx area terminals, gusty southerly afternoon winds at KBLH, and stronger westerly sundowner winds at KIPL again Wed evening. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Friday through Tuesday: Dry and persistent southwesterly flow will maintain seasonable temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds peaking at 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...MO AVIATION...Percha FIRE WEATHER...Sawtelle
  [top] Area Forecast Discussion National Weather Service Tucson AZ 145 AM MST WED JUL 6 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions nearly area- wide Sunday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Water vapor imagery and 06/00Z upper-air plots continue to show an east to west oriented ridge axis that extends from west Texas across northern Chihuahua Mexico and into south central Sonora and across central Baja. IR satellite imagery shows mostly clear skies across Arizona with a decaying storm complex to our south over eastern and southern portions of Sonora and northwestern parts of Chihuahua. The current synoptic setup continues to result in a dry westerly flow aloft across the Desert Southwest. The PW from the 06/00Z KTWC sounding was only 0.76 inches, compared to 1.28 inches from 24 hours ago. The U of A GPS PW for Tucson as of 05Z was just a tad above 0.75 inches, while the 06Z CIRA LPW Total was 0.8 inches. However, this is about to change as the CIRA LPW Total shows values of over 1.5 inches just to the south of the Cochise county border. In addition, values of 2.0+ inches can be seen near and to the east of MMHO (Hermosillo, Mexico) and values approaching 3 inches over southern Sonora. That said, the GFS has been advertising a fairly significant increase in moisture and thus POPS for today through Thursday as return flow along the western portion of the ridge ushers in moisture. The latest model runs are beginning to show better agreement than the past few days. The 06/00Z run of the NAM shows a very significant increase in the POP numbers from just the 05/12Z run, going from 3 percent for Tucson this afternoon to 34 percent. The GFS POP numbers have maintained consistency with values of around 20-30 percent for this afternoon and evening and continuing a solid chance category POPs through Thursday. ECMWF shows a slight increase from single digits to the slight chance category through Friday. At any rate, the 06/00Z run of the U of A WRF/NAM shows development over southwestern Cochise county by around Noon today and spreading into eastern Santa Cruz county and eastern Pima by late in the afternoon and/or early evening. The WRF/GFS shows initial development in the same general location, but more intense and spreading farther north into the Tucson metro and perhaps into central parts of Pima county. Based on all of this recent information, I did increase POPs for today through Thursday. Confidence is moderate to high that at least scattered storms will develop from around the Nogales area toward Douglas and eastward. The tricky part is just how far to the north/northwest will the convection develop. There will be a fairly tight POP gradient across my forecast area into the Phoenix area where they are showing virtually no chance of precipitation. I did adjust the forecast to show isolated activity today for Tucson, but depending on just how quickly the moisture moves in and what the 06/12Z KTWC sounding reveals will help determine if that category of POP is too low, or not. Day shift will have to see how things evolve and may have to make adjustments to increase POPs farther north and west than what I currently have in the forecast. The threat for showers and thunderstorms will diminish Friday, with most of the threat along the border with New Mexico and between Nogales and Douglas, but even then only isolated activity expected. Virtually no threat of storms Saturday through early next week as the ridge sets up to our south again, resulting in a dry south to westerly flow aloft. For Tucson, high and low temperatures will generally be at or slightly above normal through the forecast period. && .AVIATION...VALID THRU 07/12Z. SCT clouds at 8-12k ft AGL with BKN conditions mainly S and E of KTUS this afternoon/evening. Isolated-scattered -SHRA/-TSRA this afternoon mainly E of a KTUS-KOLS line, with some producing gusty winds and brief MVFR conditions. Otherwise, sfc winds will generally be terrain driven at 12 kts or less this morning, becoming wly/swly at 10-14 kts with gusts to around 20 kts this afternoon. Light and terrain driven winds will then resume during the overnight hours. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect better coverage of showers and storms today through Friday, with some developing as far north as the I-10 corridor including Tucson. Storms will be capable of producing gusty and erratic winds to 40 mph. Drying will then occur once again this weekend. Outside of convection, 20-ft winds will generally favor diurnal patterns at 15 mph or less, with some enhancement in areas where afternoon westerly/northwesterly flow is the norm. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...Mollere AVIATION/FIRE WEATHER...French Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Tucson AZ 145 AM MST WED JUL 6 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions nearly area- wide Sunday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Water vapor imagery and 06/00Z upper-air plots continue to show an east to west oriented ridge axis that extends from west Texas across northern Chihuahua Mexico and into south central Sonora and across central Baja. IR satellite imagery shows mostly clear skies across Arizona with a decaying storm complex to our south over eastern and southern portions of Sonora and northwestern parts of Chihuahua. The current synoptic setup continues to result in a dry westerly flow aloft across the Desert Southwest. The PW from the 06/00Z KTWC sounding was only 0.76 inches, compared to 1.28 inches from 24 hours ago. The U of A GPS PW for Tucson as of 05Z was just a tad above 0.75 inches, while the 06Z CIRA LPW Total was 0.8 inches. However, this is about to change as the CIRA LPW Total shows values of over 1.5 inches just to the south of the Cochise county border. In addition, values of 2.0+ inches can be seen near and to the east of MMHO (Hermosillo, Mexico) and values approaching 3 inches over southern Sonora. That said, the GFS has been advertising a fairly significant increase in moisture and thus POPS for today through Thursday as return flow along the western portion of the ridge ushers in moisture. The latest model runs are beginning to show better agreement than the past few days. The 06/00Z run of the NAM shows a very significant increase in the POP numbers from just the 05/12Z run, going from 3 percent for Tucson this afternoon to 34 percent. The GFS POP numbers have maintained consistency with values of around 20-30 percent for this afternoon and evening and continuing a solid chance category POPs through Thursday. ECMWF shows a slight increase from single digits to the slight chance category through Friday. At any rate, the 06/00Z run of the U of A WRF/NAM shows development over southwestern Cochise county by around Noon today and spreading into eastern Santa Cruz county and eastern Pima by late in the afternoon and/or early evening. The WRF/GFS shows initial development in the same general location, but more intense and spreading farther north into the Tucson metro and perhaps into central parts of Pima county. Based on all of this recent information, I did increase POPs for today through Thursday. Confidence is moderate to high that at least scattered storms will develop from around the Nogales area toward Douglas and eastward. The tricky part is just how far to the north/northwest will the convection develop. There will be a fairly tight POP gradient across my forecast area into the Phoenix area where they are showing virtually no chance of precipitation. I did adjust the forecast to show isolated activity today for Tucson, but depending on just how quickly the moisture moves in and what the 06/12Z KTWC sounding reveals will help determine if that category of POP is too low, or not. Day shift will have to see how things evolve and may have to make adjustments to increase POPs farther north and west than what I currently have in the forecast. The threat for showers and thunderstorms will diminish Friday, with most of the threat along the border with New Mexico and between Nogales and Douglas, but even then only isolated activity expected. Virtually no threat of storms Saturday through early next week as the ridge sets up to our south again, resulting in a dry south to westerly flow aloft. For Tucson, high and low temperatures will generally be at or slightly above normal through the forecast period. && .AVIATION...VALID THRU 07/12Z. SCT clouds at 8-12k ft AGL with BKN conditions mainly S and E of KTUS this afternoon/evening. Isolated-scattered -SHRA/-TSRA this afternoon mainly E of a KTUS-KOLS line, with some producing gusty winds and brief MVFR conditions. Otherwise, sfc winds will generally be terrain driven at 12 kts or less this morning, becoming wly/swly at 10-14 kts with gusts to around 20 kts this afternoon. Light and terrain driven winds will then resume during the overnight hours. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect better coverage of showers and storms today through Friday, with some developing as far north as the I-10 corridor including Tucson. Storms will be capable of producing gusty and erratic winds to 40 mph. Drying will then occur once again this weekend. Outside of convection, 20-ft winds will generally favor diurnal patterns at 15 mph or less, with some enhancement in areas where afternoon westerly/northwesterly flow is the norm. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ PUBLIC...Mollere AVIATION/FIRE WEATHER...French Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Flagstaff AZ 1012 PM MST TUE JUL 5 2016 .SYNOPSIS...West to southwest flow across the region will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains and portions of northern Gila county Thursday through Saturday. && .DISCUSSION...Winds have dropped off this evening, and updates were made to reduce the winds. Cloud cover was also reduced for the overnight time period. Breezy to windy conditions develop on Wednesday as a trough goes by to the north. Near critical fire weather conditions will be possible along and west northwest of a line from Prescott to Winslow to Kayenta. && .PREV DISCUSSION /321 PM MST/...Mostly dry weather with near average early July temperatures will persist through the 7 day forecast period. A trough moving through the Pacific Northwest will bring elevated southwest winds to the area Wednesday. Wind speeds will be slightly higher Wednesday than today, with gusts approaching 35 mph mainly from Flagstaff north. These increased winds combined with low afternoon humidity will cause near critical fire weather conditions generally from the I-40 corridor north. Dry west to southwest flow continues through the week with the only chance for afternoon thunderstorms over the White Mountains where enough moisture creeps in from the south. The active pattern continues to our north as an unseasonably cold low pressure system moves through the northwestern U.S. For Arizona, this will continue to bring dry and breezy weather with perhaps another notable increase in winds on Sunday. && .AVIATION...For the 06Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will redevelop aft 16Z Wed and then dcrs aft sun set Wed evening. Wind gusts of 30-35 kts expected Wed afternoon thru early evening before sunset. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A mostly dry west to southwest flow will continue. The only chance for afternoon thunderstorms will be over the White Mountains region Thursday. An increase in southwest winds combined with low humidity on Wednesday will result in near critical fire weather conditions generally from Flagstaff north. .Friday through Sunday...A chance for afternoon thunderstorms will continue across the White Mountains. Otherwise, dry weather with breezy afternoons and near average temperatures can be expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...TC/MCS AVIATION...TC FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Flagstaff AZ 1012 PM MST TUE JUL 5 2016 .SYNOPSIS...West to southwest flow across the region will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains and portions of northern Gila county Thursday through Saturday. && .DISCUSSION...Winds have dropped off this evening, and updates were made to reduce the winds. Cloud cover was also reduced for the overnight time period. Breezy to windy conditions develop on Wednesday as a trough goes by to the north. Near critical fire weather conditions will be possible along and west northwest of a line from Prescott to Winslow to Kayenta. && .PREV DISCUSSION /321 PM MST/...Mostly dry weather with near average early July temperatures will persist through the 7 day forecast period. A trough moving through the Pacific Northwest will bring elevated southwest winds to the area Wednesday. Wind speeds will be slightly higher Wednesday than today, with gusts approaching 35 mph mainly from Flagstaff north. These increased winds combined with low afternoon humidity will cause near critical fire weather conditions generally from the I-40 corridor north. Dry west to southwest flow continues through the week with the only chance for afternoon thunderstorms over the White Mountains where enough moisture creeps in from the south. The active pattern continues to our north as an unseasonably cold low pressure system moves through the northwestern U.S. For Arizona, this will continue to bring dry and breezy weather with perhaps another notable increase in winds on Sunday. && .AVIATION...For the 06Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will redevelop aft 16Z Wed and then dcrs aft sun set Wed evening. Wind gusts of 30-35 kts expected Wed afternoon thru early evening before sunset. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A mostly dry west to southwest flow will continue. The only chance for afternoon thunderstorms will be over the White Mountains region Thursday. An increase in southwest winds combined with low humidity on Wednesday will result in near critical fire weather conditions generally from Flagstaff north. .Friday through Sunday...A chance for afternoon thunderstorms will continue across the White Mountains. Otherwise, dry weather with breezy afternoons and near average temperatures can be expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...TC/MCS AVIATION...TC FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Tucson AZ 845 PM MST TUE JUL 5 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions area-wide Monday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Still looking at a few showers and thunderstorms near the International Border around KDUG. Otherwise, skies were mostly clear late this evening. The current forecast calls for a little more thunderstorm activity tomorrow and the next few days. This looks reasonable based on the latest model solutions. Thus, no updates necessary this evening. && .AVIATION...VALID THRU 07/06Z. Somewhat greater coverage of -TSRA/-SHRA will then occur Wednesday afternoon, with isolated to scattered -TSRA/-SHRA mainly from KTUS vicinity east and south to the New Mexico/International borders. Mostly clear skies late tonight into Wednesday morning. Scattered to broken clouds at 10k-15k ft msl Wednesday afternoon. Surface wind Wednesday afternoon will generally be wly at 10-15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Isolated to scattered showers and thunderstorms will occur from Tucson eastward and southward Wednesday through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions will prevail area-wide Monday into Tuesday. Otherwise, 20-foot winds will generally be terrain driven at less than 15 mph into early next week. && .PREV DISCUSSION...Some increase in showers/tstms is expected Wednesday into Friday, with the favored period during the afternoon/evening hours. Have noted that the GFS continued to befairly more robust to markedly more robust regarding precip chances versus the NAM/ECMWF/CMC solutions. For this forecast package, made only minor adjustments to the inherited gridded data PoP fields.Thus, isolated to scattered showers/tstms from Tucson eastward/southward Wednesday thru Friday with dry conditions across western/central Pima County and south-central Pinal County. Have maintained a slight chance of showers/ tstms Saturday across the White Mountains and far southeastern sections. Thereafter, the GFS/ECMWF/CMC were nearly identical with depicting a closed upper low over the Pacific Northwest Sunday. A tighter mid- level gradient should translate into stronger wly flow aloft, and shunt deeper moisture well east of this forecast area. Although the upper flow will weaken considerably by next Tuesday as high pressure aloft builds over the area, dry conditions are expected to continue. Thus, have continued with precip-free conditions area-wide Sunday into next Tuesday. Expect only very minor daily temp changes, and high temps will generally be within a couple of degs or so of normal into early next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Phoenix AZ 835 PM MST TUE JUL 5 2016 .SYNOPSIS... A break in the Monsoon pattern will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona next week Wednesday and Thursday, storm chances will be limited to southeast Arizona. Otherwise, expect dry conditions with near, to slightly above, normal temperatures. && .DISCUSSION... Another very quiet evening across our cwa, with westerly flow all the way through the column keeping monsoon moisture and thunderstorms well off to our south, mainly over extreme se AZ and northern Mexico. The combination of clear skies and a dry airmass (the 00z PSR sounding showing a pwat of only 0.81 inch) allowed temperatures to rise to near or slightly above 110F at the warmer lower desert locations again this afternoon. Tonight`s low appear that they will be very close to last night`s, in the upper-70 to mid-80 range across the lower deserts. Given current trends, other than some slight adjustments to the hourly temp/dewpoint grids, inherited forecasts are still looking good, and no updates are planned. && .PREVIOUS DISCUSSION... Rest of today through Thursday... A weak disturbance moving across AZ is producing some altocumulus plus there is some leftover lower level moisture over the higher terrain of AZ which has led to some flat cumulus development. Too stable and too little moisture for our area to see storms today. Expect they will be confined near the New Mexico border. For Wednesday and Thursday, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the broad subtropical high pressure region covering the southern CONUS/Mexico/Caribbean. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Hurricane Blas will be a non-factor. There will be some modest cooling...down to near normal/avg readings. Friday through Tuesday... The westerlies strengthen over the western states late in the week suppressing the axis of high pressure to our south . In the process, dry advection overspreads the region. This dry pattern stays in place through Tuesday. A proviso is that the deep moisture never goes exceedingly far away and remains over northwest Mexico. Thus if the intrusion of the westerlies winds up not being that strong and if convection over Sonora is more robust,then we may have more moisture to work with than anticipated. However, this scenario is really more relevant for southeast AZ as opposed to our forecast area. An upside to the influence of the westerlies is that temperatures are not looking to get out of hand despite the dry air. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Strong high pressure aloft and weak sfc pressure gradients to keep skies mainly clear through the taf period. Winds to mainly follow typical diurnal trends, with gusty afternoon westerly breezes at the Phx area terminals, gusty southerly afternoon winds at KBLH, and stronger westerly sundowner winds at KIPL again Wed evening. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Dry and persistent southwesterly flow aloft will maintain seasonably hot high temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds with gusts of 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Percha/AJ AVIATION...Percha FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Tucson AZ 330 PM MST TUE JUL 5 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions area-wide Monday into next Tuesday. Daytime temperatures will be quite close to seasonal normals. && .DISCUSSION...Isolated showers and thunderstorms will occur mainly near the international border south-to-southeast of Tucson this evening. These showers/tstms will end by midnight followed by clear skies or mostly clear skies late tonight into Wednesday morning. Some increase in showers/tstms is expected Wednesday into Friday, with the favored period during the afternoon/evening hours. Have noted that the GFS continued to be fairly more robust to markedly more robust regarding precip chances versus the NAM/ECMWF/CMC solutions. For this forecast package, made only minor adjustments to the inherited gridded data PoP fields. Thus, isolated to scattered showers/tstms from Tucson eastward/southward Wednesday thru Friday with dry conditions across western/central Pima County and south- central Pinal County. Have maintained a slight chance of showers/ tstms Saturday across the White Mountains and far southeastern sections. Thereafter, the GFS/ECMWF/CMC were nearly identical with depicting a closed upper low over the Pacific Northwest Sunday. A tighter mid- level gradient should translate into stronger wly flow aloft, and shunt deeper moisture well east of this forecast area. Although the upper flow will weaken considerably by next Tuesday as high pressure aloft builds over the area, dry conditions are expected to continue. Thus, have continued with precip-free conditions area-wide Sunday into next Tuesday. Expect only very minor daily temp changes, and high temps will generally be within a couple of degs or so of normal into early next week. && .AVIATION...VALID THRU 07/00Z. Expect isolated -TSRA/-SHRA this evening mainly near the international border southeast of KTUS. The best chance of -TSRA/-SHRA will be near the KDUG terminal, and perhaps further west and northwest to KFHU and KALK. However, the probability of occurrence is too low to include in the TAFs. Somewhat greater coverage of -TSRA/-SHRA will then occur Wednesday afternoon, with isolated to scattered -TSRA/-SHRA mainly from KTUS vicinity east and south to the New Mexico/International borders. Otherwise, west to northwest of KTUS expect clear skies to scattered clouds above 20k ft msl thru the period. KTUS vicinity east-to-south, a few to scattered clouds at 10k-15k ft msl into this evening followed by decreasing clouds with mostly clear skies late tonight into Wednesday morning. Scattered to broken clouds at 10k-15k ft msl Wednesday afternoon. Surface wind this evening and Wednesday afternoon will generally be wly at 10-15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Isolated to scattered showers and thunderstorms will occur from Tucson eastward and southward Wednesday through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions will prevail area-wide Monday into Tuesday. Otherwise, 20-foot winds will generally be terrain driven at less than 15 mph into early next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson Francis
Area Forecast Discussion National Weather Service Flagstaff AZ 321 PM MST TUE JUL 5 2016 .SYNOPSIS...West to southwest flow across the region will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains. && .DISCUSSION...Mostly dry weather with near average early July temperatures will persist through the 7 day forecast period. A trough moving through the Pacific Northwest will bring elevated southwest winds to the area Wednesday. Wind speeds will be slightly higher Wednesday than today, with gusts approaching 35 mph mainly from Flagstaff north. These increased winds combined with low afternoon humidity will cause near critical fire weather conditions generally from the I-40 corridor north. Dry west to southwest flow continues through the week with the only chance for afternoon thunderstorms over the White Mountains where enough moisture creeps in from the south. The active pattern continues to our north as an unseasonably cold low pressure system moves through the northwestern U.S. For Arizona, this will continue to bring dry and breezy weather with perhaps another notable increase in winds on Sunday. && .AVIATION...For the 00Z package...VFR conditions will continue over the next 24 hrs. Breezy SW winds will diminish after sunset tonight and redevelop aft 16Z Wed. Wind gusts of 30-35 kts expected Wed afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A mostly dry west to southwest flow will continue. The only chance for afternoon thunderstorms will be over the White Mountains region Thursday. An increase in southwest winds combined with low humidity on Wednesday will result in near critical fire weather conditions generally from Flagstaff north. .Friday through Sunday...A chance for afternoon thunderstorms will continue across the White Mountains. Otherwise, dry weather with breezy afternoons and near average temperatures can be expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...MCS AVIATION...MCS FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Phoenix AZ 249 PM MST TUE JUL 5 2016 .SYNOPSIS... A break in the Monsoon pattern will continue into next week. While there will be a temporary incursion of moisture into portions of Arizona next week Wednesday and Thursday, storm chances will be limited to southeast Arizona. Otherwise, expect dry conditions with near, to slightly above, normal temperatures. && .DISCUSSION... Rest of today through Thursday... A weak disturbance moving across AZ is producing some altocumulus plus there is some leftover lower level moisture over the higher terrain of AZ which has led to some flat cumulus development. Too stable and too little moisture for our area to see storms today. Expect they will be confined near the New Mexico border. For Wednesday and Thursday, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the broad subtropical high pressure region covering the southern CONUS/Mexico/Caribbean. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Hurricane Blas will be a non-factor. There will be some modest cooling...down to near normal/avg readings. Friday through Tuesday... The westerlies strengthen over the western states late in the week suppressing the axis of high pressure to our south . In the process, dry advection overspreads the region. This dry pattern stays in place through Tuesday. A proviso is that the deep moisture never goes exceedingly far away and remains over northwest Mexico. Thus if the intrusion of the westerlies winds up not being that strong and if convection over Sonora is more robust,then we may have more moisture to work with than anticipated. However, this scenario is really more relevant for southeast AZ as opposed to our forecast area. An upside to the influence of the westerlies is that temperatures are not looking to get out of hand despite the dry air. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Winds will favor a normal diurnal sequence with occasional wind gusts of 15 to 20 kts. through the early evening--although more frequent wind gusts are likely for the southeast California terminals. Otherwise skies will remain mostly clear with few to sct mid and high clouds throughout the period. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Dry and persistent southwesterly flow aloft will maintain seasonably hot high temperatures through Tuesday along with little to no chance of rain. Minimum humidities will show little change and favor the 7 to 12 percent range. Gusty southwest and upslope winds with gusts of 15 to 20 mph can be expected each afternoon, although higher gusts up to 20 to 25 mph are in store for Saturday and Sunday. Overnight recoveries will remain fair. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...AJ AVIATION...Sawtelle FIRE WEATHER...Sawtelle
Area Forecast Discussion National Weather Service Flagstaff AZ Issued by National Weather Service Las Vegas NV 911 AM MST TUE JUL 5 2016 .SYNOPSIS...Westerly flow across the southwest will bring warm and mostly dry conditions through the week with only a slight chance of afternoon showers and thunderstorms over the White Mountains. && .UPDATE...Overall the forecast is in good shape, with no updates planned this morning. Dry southwest flow remains in control with breezes expected each afternoon. && .PREV DISCUSSION /349 AM MST/...A drying west-southwesterly flow will persist over the next several days across northern Arizona. This will lead to fair and generally dry, but somewhat breezy, weather for much of the coming week. Near normal temperatures are also anticipated. While intermittent pushes of moisture may produce a slight chance for thunderstorms over far eastern Arizona, the pattern looks typical for an extended monsoonal break through the 7- day forecast. && .AVIATION...For the 18Z Package...Expect VFR conditions over the next 24 hrs, with breezy south to southwest winds each afternoon. A slight chance of an afternoon -SHRA/-TSRA over the White Mtns southeast of KSOW remains possible. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A drier southwesterly flow regime will limit any chance for a shower or storm to the White Mountains through Wednesday. Breezy afternoon winds will develop, with the highest wind speeds Wednesday as a trough passes north of the state. Thursday through Saturday...A chance for afternoon thunderstorms exists each day across the White Mountains. Elsewhere...dry weather with breezy afternoons expected. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ UPDATE...NWS Las Vegas PUBLIC...KD AVIATION...JJ FIRE WEATHER...JJ For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Phoenix AZ 904 AM MST TUE JUL 5 2016 .SYNOPSIS... Unseasonably dry air will continue to filter into the region as the pattern will transition away from a typical summer monsoon appearance. Temperatures will remain in a near normal range throughout the week under mostly clear skies. Only a modest chance of showers will exist through southeast and eastern Arizona during the midweek period, with virtually no chance of rain at lower elevations from central Arizona through southern California. && .DISCUSSION... Some of the larger circulation features over western North America and northeast Pacific include troughing centered over the Canadian Rockies (extending well into the NW CONUS), a large anticyclone west of the trough, and a very broad region of high pressure with an axis extending from west of Baja Mexico to east of Florida (containing multiple anticyclonic circulations). With troughing to the northwest and the axis of high pressure just to the south, our forecast area is largely within southwesterly flow aloft. There is a weak disturbance within that southwesterly flow which is producing some altocumulus. However, the 12Z soundings show that this disturbance will not be able to do much of anything else given how warm aloft we are and the drying that has taken place in the lower levels. Thus, we will have another very warm day with storm activity limited to areas well outside of our territory (near the New Mexico border). For Wed and Thu, the models depict the westerlies weakening slightly along with a shuffling of the anticyclonic centers within the high pressure region over/near us. This allows for a temporary incursion of deep moisture into southeast AZ with only very slight storm chances brushing our easternmost areas. Made some subtle upward adjustments to the temperatures for today otherwise, forecasts in good shape. && .PREVIOUS DISCUSSION...Issued 145 am MST/PDT High pressure remains situated over northern Chihuahua early this morning while several shortwaves continue to carve out longwave troughing over the Pacific Northwest. This pattern configuration will only reinforce southwest/westerly flow throughout the SW Conus with an overall anti- cyclonic subsident regime. Boundary layer moisture also continues to be eroded with 00Z KPSR sounding data sampling an anemic 6 g/kg sfc-H7 mixing ratio, while KTWC data was only slightly more supportive for convective development at 8 g/kg. However, unusually warm temperatures aloft have been amplifying with H5 readings spiking at -4C and falling near the climatological 90th percentile capping any deep convection. This general pattern will essentially hold for the entire week keeping all but the southeast portions of Arizona devoid of thunderstorms (much less for all but afternoon fair weather mountain cumulus). The operational GFS still maintains a forecast of more robust Sonoran outflow advecting marginally better moisture profiles northward towards Pinal and Gila counties Wednesday and Thursday. However, trends in this operational run have definitely been towards a lower magnitude and less influential moisture push with only 8 g/kg materializing in the sfc-H7 layer. Thus, other than a brief shower/virga over far southeast Gila County, saw no justifiable reason to include any pops through the remainder of the forecast area into the weekend. One positive of this scenario is unlike most mid-monsoon season pattern breakdowns, this convectively inactive period will feature H5 heights depressed near 592dm and afternoon H8 temperatures only hovering between +25C and +29C. Typically, breaks in thunderstorm activity in July would result in near record highs, but model output emphatically supports temperatures near to only slightly above average throughout the week. In fact, spread among all post processed raw and numerical guidance persists in an extremely narrow range yielding excellent forecast confidence. Convection will continue to remain thoroughly absent from the forecast area well into next week as larger negative height anomalies develop over the Pacific Northwest. This will exacerbate westerly flow through the intermountain west and SW Conus further eliminating any sense of quality boundary layer moisture across the forecast area. There is strong evidence that sfc dewpoints through the weekend and into early next week fall into the 30s with total column Pwats descending towards 0.50 inches (climatologically near the 10th percentile for early/mid July). Thus, instead of entering deeper into monsoon flow of mid July, the atmosphere is actually regressing more towards an early June dry pattern. Though ensemble spread begins to grow towards the middle of next week, it may very well be until the end of next week at the earliest before sufficient moisture can return north and storm chances reenter the forecast picture. && .AVIATION... South-Central Arizona Including KPHX, KIWA, and KSDL, and Southeast California/Southwest Arizona including KIPL and KBLH: Dry westerly flow aloft with only few to sct high clouds at all area terminals. Winds to mainly follow typical diurnal trends, with some afternoon gustiness likely, especially at KBLH. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Thursday through Monday: Dry southwesterly flow aloft will be in place through early next week. Minimum humidity values will be at or below 10% at most lower desert locations. Overnight recovery will be only fair. Surface winds will favor south-southwesterly in the afternoon and evening with gusts in the teens. Overall, the pattern is more characteristic of June rather than July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...AJ PREVIOUS DISCUSSION...MO AVIATION...Kuhlman FIRE WEATHER...AJ
Area Forecast Discussion National Weather Service Tucson AZ 900 AM MST TUE JUL 5 2016 .SYNOPSIS...A relatively dry air mass with westerly flow aloft will continue to limit thunderstorm coverage today. More moisture will increase thunderstorm chances the second half of the week. Another drier and warmer pattern moves in for next weekend. && .DISCUSSION...IR/Visible satellite imagery and surface observations depicted clear skies across much of southeast Arizona at this time. A few mid-level clouds were noted northwest of Tucson in the vicinity of Picacho Peak, and near the International border adjacent Cochise County. Dewpoints at lower elevations valid 15Z ranged from the 50s-lower 60s, and these temps were nearly identical to 24 hours ago. Surface temps valid 15Z were also essentially unchanged versus this time Monday. 05/12Z KTWC sounding total precip water value of 1.11 inches increased only 0.04 inch versus 24 hours ago. The column was nearly saturated around 600 mb but was quite dry in the surface-700 mb layer and above 500 mb. 05/12Z upper air plots depicted a 500 mb ridge axis that extended from west of northern Baja California eastward to Florida. Meanwhile, a belt of westerlies encompassed the northern CONUS with a 559 dm low centered over British Columbia. Light wly/swly flow aloft prevailed across southeast Arizona. The 12Z Univ. of AZ WRF-NAM was similar to the HRRR in depicting the initial development for showers/tstms late this morning or early this afternoon to occur near the Chiricahua Mountains in eastern Cochise County, or perhaps further west near the Huachuca Mountains in southwestern Cochise County. The bulk of showers/tstms later this afternoon and evening is progged to occur generally across the New Mexico bootheel, but some precip echoes were progged to be further west into about the southeast one quarter of Cochise County. Based on these solutions, see no reason to tamper with the official forecast that depicts isolated showers/tstms this afternoon/evening to occur from near Nogales eastward to the Chiricahua Mountains, or generally near the International border adjacent eastern Santa Cruz/ Cochise Counties. Dry conditions will prevail elsewhere, with high temps this afternoon virtually identical to temps achieved Monday afternoon. Please refer to the additional sections for further detail. && .AVIATION...VALID THRU 06/18Z. Expect isolated -TSRA/-SHRA this afternoon and evening mainly near the International border southeast of KTUS. The best chance of -TSRA/-SHRA will be near the KDUG terminal, and perhaps further west and northwest to KFHU and KALK. However, the probability of occurrence is too low to include in the TAFs. Otherwise, west to northwest of KTUS expect clear skies to scattered clouds above 20k ft msl thru the period. KTUS vicinity east-to-south few to scattered clouds at 10k-15k ft msl into this evening followed by decreasing clouds with mostly clear skies late tonight into early Wednesday morning. Surface wind this afternoon will generally be wly at 10-15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Enough moisture will linger for thunderstorms near the International border again today, with dry conditions elsewhere. Another brief push of moisture will bring increased coverage of showers and thunderstorms from near Tucson south and east Wednesday into Friday. Drying will then occur once again this weekend. 20-ft winds will generally favor diurnal patterns at 15 mph or less, with some enhancement in areas where afternoon westerly/northwesterly flow is the norm. && .PREV DISCUSSION /150 AM MST/...Water vapor imagery and 05/00Z upper- air plots show a sprawling ridge that extends generally west to east from the central Baja Peninsula across northern Mexico and into west Texas. This has resulted in a continuation of a dry westerly flow aloft across the desert southwest as evidenced on the 05/00Z KTWC sounding. The PW on the sounding was up a bit from 12 to 24 hours ago, with a value of 1.28 inches, which was about two-tenths of an inch greater. Both the CIRA LPW Total and the U of A GPS PW show a value as of 06Z of just a tad over an inch. Models indicate that the ridge to our south will shift eastward through early Wednesday to a position over the southern plains with the ridge axis extending westward across northern Mexico. As this shift occurs, return flow on the western flank of the ridge will allow moisture to increase during the middle to latter part of the week. Therefore, expect thunderstorm chances to increase mainly Wednesday into Thursday, with the focus for thunderstorms being from around Nogales to Douglas, with the activity spreading a bit farther north Thursday. For now it looks like the farthest northwestern extent of the storms will be around the Tucson area, with very little threat west and north of the city. Even so, it only looks like isolated coverage for the Tucson metro. However, this could change depending on what subsequent model runs indicate, so stay tuned. Confidence is not high at this point with the GFS being the most robust model in wanting to bring in the threat for storms, whereas the NAM and ECMWF, not so much. Just one example, looking at MOS POP numbers for Tucson, the NAM shows POPS in the single digits for Wednesday through Thursday, whereas the GFS has 12-hour POPS of 14, 39 and 21 percent for Wednesday, Wednesday night and Thursday, respectively. ECMWF is much closer to the NAM numbers. So, sorta went with a blend, but not yet close to the GFS values, especially for Wednesday night. With subsequent model runs, the forecast may change between now and the middle to latter part of the week. Confidence is moderate to high at this point that areas along the international border will see at least scattered convection. By the weekend a low pressure system will begin to affect the Pacific northwest as the ridge becomes reestablished to our south again, resulting in a drying trend for the weekend and into early next week. For Tucson, high temperatures will range from 2 to 4 degs above normal today and then near normal Wednesday through Friday before becoming around 2 to 4 degs above normal again for the weekend and early next week. Low temps will range from 4 to 6 degs above normal Wednesday morning, then around 2 to 4 degs above normal thereafter. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson DISCUSSION...Francis PREVIOUS DISCUSSION...Mollere AVIATION/FIRE WEATHER...French Area Forecast Discussion National Weather Service Tucson AZ 350 PM MST WED JUL 6 2016 .SYNOPSIS...Isolated to scattered afternoon and evening thunderstorms will prevail mainly east to south of Tucson through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions area-wide Sunday into next Wednesday. && .DISCUSSION...Scattered showers and thunderstorms were occurring from the far southern portion of the Tucson metro area eastward and southward to the New Mexico/international borders at this time. Rainfall amounts have generally been around one quarter of an inch, though a few amounts to around one half of an inch have occurred. Brief wind gusts to near 30 mph have also been observed. Have noted that several HRRR solutions since 18Z have gradually trended downward in coverage and intensity of showers/tstms for the rest of this afternoon and evening versus HRRR solutions prior to 18Z. Storm Prediction Center Mesoscale Analysis suggests some stabilization has occurred during the past 1-2 hours, with MUCAPES of around 1000 J/kg versus values approaching 1500 J/kg near the international border earlier this afternoon. For this forecast issuance, have continued with scattered showers/ tstms from Tucson southward this evening, then a slight chance of showers/tstms mainly from Tucson east and south late tonight. Am somewhat concerned about any showers/tstms to occur late tonight, since the GFS was the only model to depict measurable precip to potentially occur. Expect isolated to scattered showers/tstms Thursday afternoon/evening from Tucson east and south, then a slight chance of showers/tstms east of Tucson late Thursday night into Friday evening. Have maintained a slight chance of showers/tstms Saturday across the White Mountains and far southeastern sections. Thereafter, the GFS/ECMWF/CMC were nearly identical with depicting a closed upper low over Oregon Sunday. A tighter mid-level gradient will translate into stronger wly flow aloft, and shunt deeper moisture well east of this forecast area. High pressure aloft is progged to build over the southwestern CONUS Tue-Wed, and the upper flow will weaken in response. However, the GFS/ECMWF depicted a very dry regime across southeast Arizona, and precip-free conditions are expected area-wide into the middle of next week. Only minor daily temp changes will prevail into the middle of next week as well. && .AVIATION...VALID THRU 08/00Z. Scattered -TSRA/-SHRA will occur from KTUS vicinity east and south to the New Mexico/international borders this evening and again Thursday afternoon. A slight chance of -TSRA/-SHRA exists late tonight into Thursday morning, mainly east to south of KTUS. Otherwise, clear skies to scattered clouds above 20k ft msl will prevail west to northwest of KTUS thru Thursday afternoon. Surface wind this evening and Thursday afternoon will generally be wly at 10- 15 kts with gusts to 20 kts. Otherwise, surface wind will be variable in direction at less than 10 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Isolated to scattered showers and thunderstorms will occur from Tucson eastward and southward Wednesday through Friday. A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday, then dry conditions will prevail area-wide Sunday through next Wednesday. Apart from brief gusty thunderstorm outflows, 20-foot winds will generally be terrain driven at less than 15 mph into the middle of next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
331 PM CDT WED JUL 6 2016 .SHORT TERM...(This Evening through Thursday) Issued at 328 PM CDT WED JUL 6 2016 Effects of northeast and southern KS convection this morning has left airmass over the forecast area drier and not as hot as previously forecast. Thus, have struggled to have HI values approach 100 degrees across most of the area and have cancelled Heat Advisory. Main questions for the forecast for tonight and Thursday are: What will be the mechanism for potential thunderstorms affecting us tonight and Thursday, and whether temps and dewpoints will reach high enough to meet heat index criteria Thursday afternoon? For the latter question, currently forecasting temps in the mid 90s in the north and east with upper 90s possible over portions of central KS. Dewpoints are forecast to range from the lower to possibly middle 70s in the east, while upper 60s to near 70 is more realistic over central KS. This would lead to max HI values from 100 to 105 nearing advisory criteria. However, there is enough uncertainty in reaching these values if we have our airmass once again modified by convective outflows and some cloudiness from overnight/morning thunderstorms near our area. Thus, have not issued an advisory for Thursday and will let midnight forecast crew decide on that as potential convective effects become less uncertain. Water vapor loop shows a weak shortwave trough over extreme western KS, and possibly another one to the northwest in northern CO. Most short and medium range models do not develop persistent convection with these features. However a few runs of the HRRR and experimental HRRR have been developing a cluster of storms over eastern CO or southwest KS and bringing the associated convection across eastern KS after midnight. Given inconsistency of these HRRR runs, have not included any significant POPs from this forecast convection. Possibly more likely scenario would be closer to going forecast, and perhaps best depicted by 12Z NAM, where an MCS is forecast to affect primarily Nebraska, with tail end affecting far nothern and northeastern KS late tonight and Thursday morning. This is what has been put in forecast grids, but developments over western KS will obviously have to be monitored for HRRR scenarios. .LONG TERM...(Thursday Night through Wednesday) Issued at 328 PM CDT WED JUL 6 2016 Strong upper wave will move across the Upper Midwest pushing a cold front across the area Thu night. Capping and stronger lift associated with the wave should keep the bulk of the precip NE of the area but will keep low chcs in the northeast given strength of wave. The front will sag into southern KS on Friday and will keep low chcs across the southern counties near the front. By Friday night into the weekend confidence in location and timing of precip is low since recent performance of models has been poor with placement of nocturnal convection. That said chcs would appear to increase at least across central KS Fri night as the thetaE advection increases atop the boundary. The area will remain within the weak upper ridge with overnight storm chcs through the weekend before a unusually strong upper trough moves into the Rockies by early next week. This trough will push a front into the region by later Monday into Tues so it would appear best chcs for organized storms would occur around that time frame. The front will hang up across the area toward mid week and with zonal flow wouldn`t be surprised to see storm chcs persist through next week. && .AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon) Issued at 1210 PM CDT WED JUL 6 2016 Very little change expected through mid day Thursday. Expect southerly winds 5 to 15 kts and VFR conditions. Very low probabilities of late night/early morning thunderstorms, most likely staying well to north of TAF sites. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...GDP LONG TERM...Omitt AVIATION...GDP