Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/26/16

Area Forecast Discussion
National Weather Service Tucson AZ
858 PM MST SAT JUN 25 2016

.SYNOPSIS...We now have enough moisture for isolated to scattered
showers and thunderstorms this weekend. A more favorable flow
regime will then provide increased coverage of showers and
thunderstorms Monday through Friday.

&&

.DISCUSSION...Water vapor imagery shows a stark contrast between a
dry mid level regime to our west and a moist airmass to the east.
This line generally extends from Flagstaff to Phoenix to Organ Pipe
National Monument. IR satellite imagery shows extensive mostly mid
level debris clouds from earlier convection that covers most of my
forecast area, with the exception of the far western portions of
Pima county.

Earlier this afternoon, isolated showers and storms developed over
the Santa Catalina and Rincon mountains and eventually drifted off
the mountains into the foothills with some gusty outflows and
moderately heavy rainfall on the northeast portion of the Tucson
metro and into the foothills. Several automated gauges reported
amounts of 0.50 inches to around 0.80 inches.

Currently, the radar mosaic from around the region indicates some
light activity from remnants of earlier convection south of the
border over eastern Santa Cruz and southwestern Cochise county and
drifting west to northwest. Additional activity is occurring in
southwestern New Mexico and drifting west, but this activity should
continue to decrease through the remainder of the evening. Will keep
a mention of a slight chance of showers and possible thunderstorms
in the forecast overnight, mainly near the borders with Mexico and
New Mexico.

As of 03Z (8 PM MST), temperatures across the region ranged from the
lower 70s near the international border, to the lower 90s over
northern and central parts of the forecast area. The Tucson
International Airport reported a temp of 89 degs after reaching an
afternoon high of 100 degs. These readings seem to be on track with
the inherited low temperature forecast, but will make some minor
adjustments to the short term hourly temperature grids to reflect
recent trends.

See the previous discussion below for details beyond tonight.

&&

.AVIATION...VALID THRU 27/06Z.
Isolated to scattered -TSRA/-SHRA again Sunday afternoon. Cloud
decks ranging from 10k- 15k ft msl. Gusty outflows possible with any
storms that develop, otherwise surface wind will generally be less
than 10 kts into Sunday. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this weekend. Greater coverage of showers and
thunderstorms should then occur Monday through next Friday.
Otherwise, daytime minimum relative humidity values will generally
range from the mid teens to around 30 percent with fair to good
nighttime recovery. 20-foot winds this weekend as well as
Wednesday through Friday will be terrain driven at less than 15
mph. 20-foot winds Monday and Tuesday will generally be from the
east at 5-15 mph with gusts of 15-20 mph. The strongest speeds
Monday and Tuesday should prevail from shortly after sunrise into
the early afternoon hours.

&&

.PREV DISCUSSION...For Sunday, some secondary consolidation in the
broad scale mean ridge position should tamp down convection with
most favored locations being the central mountains and international
border areas. Starting the day with what should still be a
relatively weaker flow will make storms initially reluctant to push
away from the mountains Sunday afternoon. However the UofA WRF-GFS
is hinting at a couple of nice strong outflows pushing west and
northwest late Sunday afternoon and early Sunday evening, filling in
valley locations and probably generating dust north of Tucson.

After that, as high pressure strengthens north of the area, the
first half of the new week should see a better flow regime (albeit
still on the weak side) for reinforcing deep moisture and importing
one or two weaknesses in the flow. This should serve to anchor the
entire week for seasonal convection.

&&

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

&&

$$

DISCUSSION...Mollere
PREVIOUS DISCUSSION...Meyer/Rasmussen

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  [top] Area Forecast Discussion National Weather Service Phoenix AZ 850 PM MST SAT JUN 25 2016 .SYNOPSIS... A very warm air mass will keep temperatures above normal through at least the first half of next week. A gradual increase in moisture will seep into portions of Arizona later this weekend and into next week, leading to a threat for showers and thunderstorms. Rainfall will initially be limited to the higher terrain, then finally move towards lower deserts as we move into next week. && .DISCUSSION... A bit of an increase in convective activity today when compared to yesterday, but still very quiet at most locations. The main moisture plume, as seen on latest water vapor satellite imagery shifted a bit to the west today, allowing an increase in thunderstorm activity over the Tucson area, where areas on the northeast side of that city saw there 1st significant rainfall of the season, with some locations seeing up to 0.75 inch late this afternoon. A few storms also developed over the Rim Country, then tried to push southeastward into southern Gila county before dissipating. One cell did develop over the higher terrain north of US 60 between Superior and Globe earlier this evening, and likely did produce some brief heavy rainfall and gusty winds before dissipating. At this hour, all that is left from these storms is a weak outflow boundary that is now moving into northern Pinal/eastern Maricopa counties. The only likely impact from this outflow is will be to jsut produce a bit of gusty winds, up to 25 mph, which will likely not be strong enough to produce any significant blowing dust. Based on current trends and latest HRRR high-res forecasts, have reduced POPS somewhat and removed blowing dust from the grids for the remainder of this evening. As far as the forecast for Sunday is concerned, based on the latest NAM/GFS model output, is still looks like it will be very similar to today, and no further updates are planned. && .PREVIOUS DISCUSSION... Tonight and Sunday... Forecast for the next 7 days are going to be quite challenging with regards to thunderstorm threats as low/mid level moisture make a slow creep from southeast AZ this weekend, west into the remainder of the state throughout next week. However for tonight and Sunday, most of our forecast area will be dry with the exception of possible isolated thunderstorms over the mountains of southern Gila County this evening, and again Sunday evening. One thing that concerns us though, the models are forecasting a large mid level inverted trof to develop over northwest Mexico by late afternoon. We cant see it in the vapor imagery, however models insist that its resultant broad cyclonic circulation will rotate the bulk of convective debris clouds from southeast AZ, into central and southern AZ tonight and Sunday morning. This will mark the beginning of the slow westward moisture push. Unfortunately the Guaymas sounding in northwest Mexico along the Gulf coast has been missing for months now, so we cant get a close look at this evolving feature from measured data, and will have to default to the models and with their predictions of midlevel moisture advection through Sunday. Monday through Saturday... A more established monsoon, in terms of moisture, is expected over the southern half of AZ. The monsoon moisture boundary from southeast AZ is expected to move into the Phoenix area by Tuesday, then toward the lower Colorado River Valley by late Wednesday. In other words, most of our southwest and south-central AZ zones will be in the monsoon soup by the middle of next week, with enough potential energy for possible convective threats, although its really the little upper level nuances/perturbations that govern any larger outbreaks, and or colliding outflow boundaries which are difficult to discern this far in advance. Therefore, as far as convective threats are concerned for next week, we found that a broad brush approach to forecasting a slight chance of convective threats nearly everywhere was best. This approach actually started on the mid shift last night and accepted. Another reason for the convective uncertainties involve the upper level nuances/perturbations. Models forecast one large 300/250 mb upper level inverted trof to move into southwest AZ from the northern Gulf of CA on Monday, with several follow-up smaller disturbances for the remainder of the week. Since the upper flow is very weak over northern Mexico, which inherently make the models less predictive or less reliable, and there are very few Mexican weather balloon soundings launched, we will take a wait and see position this far in advance before we jump on any one particular day next week that could be convectively significant. Again a broad brush slight chance of tstm approach is good for now, but hey, the monsoon will be here. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Winds to remain on the light side, mainly aob 10 kts through Sunday, following typical diurnal trends, likely becoming easterly around midnight tonight, and westerly on Sunday afternoon. Scattered to broken mid-high cloud layers to linger into Sunday as a result of debris clouds from distant thunderstorms. There is once again an outside chance that outflows from distant thunderstorms could affect the terminals on Sun Aft/Eve, but confidence is too low to include it in the tafs at this time. Southeast California/Southwest Arizona including KIPL and KBLH: Skies will remain mostly clear over both TAF sites through Sunday. Winds will remain out of the south at KBLH and out of the south to southeast at KIPL, with speeds generally aob 10 kts accompanied by a few afternoon gusts up to 15 to 20 kts. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Tuesday through Saturday... Temperatures will be on a "cooling" trend, with highs on Tuesday around 108-115F dropping into the 102-110F range by Saturday. As monsoon moisture levels increase over the region, isolated thunderstorms are possible each afternoon/evening over much of the desert southwest, with the highest chances over the higher terrain of central and eastern Arizona. Accompanying any storm that develops will be wetting rains, gusty erratic winds, and lightning. This increase in moisture will support a rise in minimum humidities, with values ranging in the 15-25 percent range each day with good overnight recoveries. Outside of gusty storm winds, speeds will range between 5 to 15 mph with a few afternoon upslope gusts up to 20 mph. && .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/Vasquez AVIATION...Percha FIRE WEATHER...Hernandez
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
404 AM CDT FRI JUN 24 2016 .SHORT TERM...(Today and Tonight) Issued at 307 AM CDT FRI JUN 24 2016 Early this morning a broad mid-level ridge remained in place across the central and southern U.S. with water vapor imagery showing an embedded shortwave over western Kansas that was helping to support a cluster of early morning storms across southwest and south central Kansas. At the surface, a warm front was stretched across east central Kansas with a few scattered showers and storms noted south of this boundary across southeast Kansas and far southwest Missouri. Models show this warm front slowly lifting northward across the CWA today. As the shortwave over western Kansas advances into eastern Kansas this morning with the warm front nearby, short-range models show the potential for some scattered storms to develop across central and east central Kansas this morning and lift northward into north central and northeast Kansas through the day. Forcing looks to be fairly weak with barely 20kts of 0-6km bulk shear through the day. While 3000-4000 J/kg of MUCAPE may be present, the weak forcing and weak shear should keep storms sub-severe today. Due to the uncertainty in the coverage of thunderstorm development amongst the short-range models, have only slight to chance PoPs in for today. With the warm front lifting into extreme northeast Kansas by early this evening, any lingering isolated to scattered storms should be focused near the NE/KS border. As a result, have PoPs diminishing from south to north this evening and expect that much of the CWA should remain predominantly dry. Another embedded shortwave is expected to develop overnight across northwest and north central Kansas with some isentropic lift noted across north central Kansas. While there may not be much moisture present yet over north central Kansas overnight into Saturday morning, felt that with the isentropic lift in place it was worth keeping some slight chance PoPs over far north central Kansas. Despite some scattered low/mid-level clouds today, expect the breezy southerly winds to aid in warm-air advection enough to support afternoon high temperatures in the low/mid 90s with heat indices in the upper 90s to around 100 degrees. The persistent southerly winds and scattered cloud cover should keep overnight low temperatures a bit warmer with lows only dropping into the low/mid 70s. .LONG TERM...(Saturday through Thursday) Issued at 307 AM CDT FRI JUN 24 2016 On Saturday, a strong upper trough will move along the Canadian border, and will be strong enough to push a cold front into the forecast area. Saturday will be hot as the thermal axis immediately in advance of the cold front builds from SW into NE Kansas. Models are in strong agreement with the timing of the front entering the area after peak heating, but there is also an expectation for storms and clouds to develop along the front and possibly cool temperatures just slightly by late day. Regardless, expect highs in the upper 90s in central KS to the middle 90s in eastern KS. Dewpoints will probably mix out a bit in this environment as well so expect max heat indices in the 98-104 range. Strong convergence along the front will likely lead to thunderstorm development, and those storms are likely to continue as the front pushes southeast into the area although it is uncertain just how widespread the coverage will remain overnight. Moderate instability is expected with weak and disorganized shear profiles. For the most part, will probably be looking for non- severe storms although in the expected hot environment, there is always that chance for sporadic severe downbursts with the strongest storms, and also some low end potential for organized bowing segments to develop with attendant wind threat. For now though, the severe risk appears marginal and is reflected as such in the SPC outlook. The cold front is likely to stall over southern parts of the area on Sunday with a rather unstable airmass expected to linger through Sunday evening. There are model suggestions of a weak short wave trough moving along the front on Sunday which could trigger another round of thunderstorm development...again in the moderate CAPE/low shear environment. A very similar scenario seems likely to play out for Monday. So, while the chances for widespread thunderstorms are not outstanding each day, the low level focus exists with some potential for upper support and have kept precip chances in the area through the period. The flow pattern becomes more northwesterly by Tuesday with cooler air filtering into northeast KS and highs finally expected to drop back into the 80s. A well-organized short wave trough is expected to move across the area from NW to SE Wednesday into Thursday and will provide the area with several chances for thunderstorms. Wind shear will be much better with this system so will want to watch the period for severe potential. Otherwise expect generally cooler temperatures through the end of the week. && .AVIATION...(For the 06Z TAFS through 06Z Friday Night) Issued at 1139 PM CDT THU JUN 23 2016 Will keep VFR forecast at this time but note thunderstorms may be near terminals periodically Friday. Enough time for next issuance to take a look but at this time confidence too low to add to forecast. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Hennecke LONG TERM...Barjenbruch AVIATION...67
Area Forecast Discussion National Weather Service Goodland KS 300 AM MDT FRI JUN 24 2016 .SHORT TERM...(Today and tonight) Issued at 222 AM MDT Fri Jun 24 2016 As the upper ridge over the plains shifts east ahead of the upper low moving east through Montana along the U.S./Canada border, a short wave trough embedded in the upper flow moves off the central Rockies and across the central high plains region during the evening and overnight hours tonight. During this time a prefrontal trough deepens along the front range ahead of a cold front that is expected to move across the forecast area early Saturday. Expect isolated to scattered thunderstorms to develop over the higher terrain to the west and move over a more favorable instability environment with more available moisture east of the deepening surface trough this evening with a marginal risk of severe thunderstorms.High temperatures today with southerly flow ahead of the surface trough will be well into the 90s. High temperatures on Saturday following the cold front will be in the 80s to lower 90s. On Saturday there may be a few lingering early morning showers and thunderstorms across eastern portions of the forecast area. Isolated storms are expected to redevelop and become scattered over the far eastern sections of the forecast area by afternoon along and ahead of the cold front where there is a more favorable shear profile and greater instability and available moisture. There is still only a marginal risk of severe thunderstorms across the southeast portion of the forecast area in the vicinity of the front. Expect highs to be back into the lower 90s on Sunday with weak westerly flow aloft and high pressure at the surface in the wake of the cold front. A few thunderstorms are being hinted at mainly along the southern extent of the forecast area in closer proximity to the stationary boundary, but have gone mostly dry across the forecast area. .LONG TERM...(Saturday through Thursday) Issued at 222 AM MDT Fri Jun 24 2016 The extended period has a very dominate ridge sitting over the western CONUS with a closed low over the far northeastern states. There is also a closed low that is sitting over the North Pacific that tries to push east, but the ridge is very strong and it doesn`t make much of a dent until Friday. As for the CWA, there are chances for precipitation everyday; with best chances on Monday and Wednesday; but still favorable chances Tuesday and Thursday. MUCAPE values get up to 2300 J/kg Monday with bulk shear around 30 kts. Wednesday has MUCAPE values of around 3500 J/kg and bulk shear up to 50 kts. In addition, Tuesday and Wednesday show to have 700 mb shortwaves that push over the region crating better lift. Overall, precipitation chances are expected next week but exact timing and intensity will become more clear as the days get closer. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1144 PM MDT Thu Jun 23 2016 VFR conditions should continue through the TAF period. Isolated showers/thunderstorms may still be possible, however confidence that this would impact KGLD has greatly diminished and trends on radar have been towards current activity weakening before reaching KMCK. Fog/stratus may be possible in eastern Colorado by 12z, but confidence is low that this would reach KGLD and VFR conditions were prevailed. Winds should increase during the afternoon Friday before decreasing again around sunset. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...LOCKHART LONG TERM...CLT AVIATION...DR
Area Forecast Discussion National Weather Service Dodge City KS 346 AM CDT FRI JUN 24 2016 .SHORT TERM...(Today and tonight) Issued at 340 AM CDT Fri Jun 24 2016 Another MCV may be developing across the area early this morning, however, it should be exiting the forecast area by sunrise. As the leftover outflow boundary will be likely well off to the east of our area and subsidence settles in across the area, a dry forecast is in place for the rest of the day. The models once again develop higher terrain surface based storms late in the day, that with weak steering flow remain in eastern Colorado and as far east as northwest Kansas by the late evening. The outflow may not modify the highs as much today as the cloud cover seemed to on Thursday, as it is more likely longer duration insolation should be seen today. .LONG TERM...(Saturday through Thursday) Issued at 340 AM CDT Fri Jun 24 2016 The next chance for focused thunderstorm development appears in the late Saturday timeframe, along a surface boundary that straddles the forecast area. These storms would likely not have significant shear or steering also and might be tied to the boundary unless they can develop a cold pool. At the same time, a closed low is shown by the models to be moving through the northern Plains, maintaining a nearly zonal flow aloft across the central Plains. Beyond that, mesoscale features become increasingly difficult to infer from the larger pattern, however the upper ridge does begin to redevelop into mid week, supporting the warmer temperatures in the 90s we`ve seen so far. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 607 PM CDT Thu Jun 23 2016 VFR conditions will prevail this evening with the possibility of a squall line moving through the area overnight. If this squall line comes to fruition, periods of MVFR conditions will be observed. Winds will generally be from the east southeast at less than 10 knots. && .PRELIMINARY POINT TEMPS/POPS... DDC 94 MMM 95 68 / 20 10 20 40 GCK 95 MMM 95 67 / 20 20 20 20 EHA 95 MMM 95 67 / 20 20 20 30 LBL 96 MMM 97 68 / 20 10 20 30 HYS 94 MMM 94 66 / 20 20 30 30 P28 95 MMM 97 73 / 20 0 10 20 && .DDC Watches/Warnings/Advisories...NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Hovorka_42
Area Forecast Discussion...Corrected National Weather Service Wichita KS 345 AM CDT FRI JUN 24 2016 .SHORT TERM...(Today through Sunday Night) Issued at 345 AM CDT Fri Jun 24 2016 Forecast Highlight: Thunderstorms anticipated for nearly all areas for most areas thru next Thu. Today: A stationary front has remained positioned along the KS/OK border throughout the night. Along & north of the front, thunderstorms havebeen ongoing, the majority of which are the remnants of a weakening MCS moving slowly east over SW KS. However, a north/south oriented cluster of thunderstorms is slowly expanding from Kay County OK to Butler County very close to a weak low-level jet. With a strong mid-upper ridge situated from the Srn Plains to Nebraska & IA, mid-level flow has been weak. As such locally heavy rains have occurred, most notably Kay County OK but rainfall rates are also increasing in Sumner & Butler counties. As a lower-deck trof slowly strengthens across Ern CO the sfc-850 mb moisture axis would shift slowly east across Ern KS. As such thunderstorms should be confined to primarily SE KS this afternoon. Tonight: As a broadening mid-level trof moves slowly east toward the TX/OK Panhandles drier air would spread NE across most of the CWA early this evening, keeping most areas rain-free. The exceptions would be the nwrn-most counties (Russell, Barton & Lincoln) where a lead mid- level short wave ejecting NE toward, then across, the CO/KS border will induce thunderstorms to redevelop over these areas. As such a few thunderstorms may reach the above-mentioned counties very early Sat Morning. Rest of the Weekend: An upper-deck cyclone that early this morning is centered over WA & OR will strengthen considerably as it surges east across the Nrn Plains. This would kick a cold front SE that may reach Central KS late Sat Night. The projected track of the upper cyclone would likely cause the front to decelerate as it moves further southeast toward the turnpike. Thunderstorms would therefore increase with the greatest increase across Central KS Sat Night. Deep-layer shear remains fairly weak which would keep the severe potential marginal at best. With a very moist & unstable airmass entrenched across the neighborhood locally severe thunderstorms cannot be ruled out. At this time, the highest potential for severe thunderstorms would be across Central KS Sat Night & Sun where closer to the srn segment of the strong ewd-surging mid-upper wave. .LONG TERM...(Monday through Thursday) Issued at 345 AM CDT Fri Jun 24 2016 With the front, though weakening, stalled in an east/west manner across KS interacting with a very moist airmass, thunderstorms would be expected for much of the upcoming work-week. Inherited forecast addresses this situaton and was therefore kept intact. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1150 PM CDT Thu Jun 23 2016 VFR conditions are expected across the area for most locations overnight into Fri. SHRA/TSRA beginning to develop near KDDC at this time just ahead of a line of convection coming east off the high plains near KGCK. Low level moisture transport out of the OK panhandle is feeding this renewed convective development, with this convection expected to make its way east-southeast late tonight into early Fri morning. Propagation vectors suggests that the strongest convection will move more SE than E, which would suggest most of this renewed convection will drift south of the KRSL, KSLN and KGBD TAFS. Plan on keeping a VCTS for KHUT and KICT for the 08-12z time frame, as extrapolation of the convection may lead it to clipping South Central KS. Still uncertain on how strong the storms will be, but if they make it to KICT and KHUT then some MVFR vsbys or cigs may be possible. After the morning convection, expect VFR conditions to return the area for FRI afternoon as the frontal boundary begins to lift back north as a warm front. Ketcham && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 94 74 98 76 / 30 10 10 30 Hutchinson 95 74 99 74 / 30 10 10 40 Newton 93 73 97 75 / 30 10 10 30 ElDorado 93 73 95 75 / 30 10 10 30 Winfield-KWLD 94 74 96 77 / 30 10 10 20 Russell 95 74 99 70 / 20 20 40 60 Great Bend 96 74 99 70 / 20 20 30 60 Salina 95 75 100 73 / 20 10 20 50 McPherson 95 74 99 74 / 20 10 20 40 Coffeyville 92 72 94 75 / 30 10 10 10 Chanute 92 72 94 75 / 30 10 10 20 Iola 91 72 94 74 / 40 10 10 20 Parsons-KPPF 92 73 94 75 / 30 10 10 10 && .ICT Watches/Warnings/Advisories... None. && $$ SHORT TERM...EPS LONG TERM...EPS AVIATION...BDK
Area Forecast Discussion...Corrected National Weather Service Wichita KS 345 AM CDT FRI JUN 24 2016 .SHORT TERM...(Today through Sunday Night) Issued at 345 AM CDT Fri Jun 24 2016 Forecast Highlight: Thunderstorms anticipated for nearly all areas for most areas thru next Thu. Today: A stationary front has remained positioned along the KS/OK border throughout the night. Along & north of the front, thunderstorms havebeen ongoing, the majority of which are the remnants of a weakening MCS moving slowly east over SW KS. However, a north/south oriented cluster of thunderstorms is slowly expanding from Kay County OK to Butler County very close to a weak low-level jet. With a strong mid-upper ridge situated from the Srn Plains to Nebraska & IA, mid-level flow has been weak. As such locally heavy rains have occurred, most notably Kay County OK but rainfall rates are also increasing in Sumner & Butler counties. As a lower-deck trof slowly strengthens across Ern CO the sfc-850 mb moisture axis would shift slowly east across Ern KS. As such thunderstorms should be confined to primarily SE KS this afternoon. Tonight: As a broadening mid-level trof moves slowly east toward the TX/OK Panhandles drier air would spread NE across most of the CWA early this evening, keeping most areas rain-free. The exceptions would be the nwrn-most counties (Russell, Barton & Lincoln) where a lead mid- level short wave ejecting NE toward, then across, the CO/KS border will induce thunderstorms to redevelop over these areas. As such a few thunderstorms may reach the above-mentioned counties very early Sat Morning. Rest of the Weekend: An upper-deck cyclone that early this morning is centered over WA & OR will strengthen considerably as it surges east across the Nrn Plains. This would kick a cold front SE that may reach Central KS late Sat Night. The projected track of the upper cyclone would likely cause the front to decelerate as it moves further southeast toward the turnpike. Thunderstorms would therefore increase with the greatest increase across Central KS Sat Night. Deep-layer shear remains fairly weak which would keep the severe potential marginal at best. With a very moist & unstable airmass entrenched across the neighborhood locally severe thunderstorms cannot be ruled out. At this time, the highest potential for severe thunderstorms would be across Central KS Sat Night & Sun where closer to the srn segment of the strong ewd-surging mid-upper wave. .LONG TERM...(Monday through Thursday) Issued at 345 AM CDT Fri Jun 24 2016 With the front, though weakening, stalled in an east/west manner across KS interacting with a very moist airmass, thunderstorms would be expected for much of the upcoming work-week. Inherited forecast addresses this situaton and was therefore kept intact. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1150 PM CDT Thu Jun 23 2016 VFR conditions are expected across the area for most locations overnight into Fri. SHRA/TSRA beginning to develop near KDDC at this time just ahead of a line of convection coming east off the high plains near KGCK. Low level moisture transport out of the OK panhandle is feeding this renewed convective development, with this convection expected to make its way east-southeast late tonight into early Fri morning. Propagation vectors suggests that the strongest convection will move more SE than E, which would suggest most of this renewed convection will drift south of the KRSL, KSLN and KGBD TAFS. Plan on keeping a VCTS for KHUT and KICT for the 08-12z time frame, as extrapolation of the convection may lead it to clipping South Central KS. Still uncertain on how strong the storms will be, but if they make it to KICT and KHUT then some MVFR vsbys or cigs may be possible. After the morning convection, expect VFR conditions to return the area for FRI afternoon as the frontal boundary begins to lift back north as a warm front. Ketcham && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 94 74 98 76 / 30 10 10 30 Hutchinson 95 74 99 74 / 30 10 10 40 Newton 93 73 97 75 / 30 10 10 30 ElDorado 93 73 95 75 / 30 10 10 30 Winfield-KWLD 94 74 96 77 / 30 10 10 20 Russell 95 74 99 70 / 20 20 40 60 Great Bend 96 74 99 70 / 20 20 30 60 Salina 95 75 100 73 / 20 10 20 50 McPherson 95 74 99 74 / 20 10 20 40 Coffeyville 92 72 94 75 / 30 10 10 10 Chanute 92 72 94 75 / 30 10 10 20 Iola 91 72 94 74 / 40 10 10 20 Parsons-KPPF 92 73 94 75 / 30 10 10 10 && .ICT Watches/Warnings/Advisories... None. && $$ SHORT TERM...EPS LONG TERM...EPS AVIATION...BDK
Area Forecast Discussion National Weather Service Wichita KS 328 AM CDT FRI JUN 24 2016 .SHORT TERM...(Today through Sunday Night) Issued at 328 AM CDT Fri Jun 24 2016 Forecast Highlight: Thunderstorms anticipated for nearly all areas for most areas thru next Thu. Today: A stationary front has remained positioned along the KS/OK border throughout the night. Along & north of the front, the majority of which are the remnants of a weakening MCS moving slowly east over SW KS. However, a north/south oriented cluster of thunderstorms is slowly expanding from Kay County OK to Butler County very close to a weak low-level jet. With a strong mid- upper ridge situated from the Srn Plains to Nebraska & IA mid-level flow has been weak. As such locally heavy rains have occurred, most notably Kay County OK but rainfall rates are also increasing in Sumner & Butler counties. As a lower-deck trof slowly strengthens across Ern CO the sfc-850 mb moisture axis would shift slowly east across Ern KS. As such the rain should be confined to SE KS this afternoon. Tonight: As a broadening mid-level trof moves slowly east toward the TX/OK Panhandles drier air would spread NE across most of the CWA early this evening, keeping most areas rain-free. The exceptions would be the nwrn-most counties, Russell, Barton & Lincoln) where a lead mid-level short wave ejecting NE toward, then across, the CO/KS border will induce thunderstorms to redevelop over these areas. As such a few thunderstorms may reach the above-mentioned counties very early Sat Morning. Rest of the Weekend: An upper-deck cyclone that early this morning is centered over WA & OR will strengthen considerably as it surges east across the Nrn Plains. This would kick a cold front SE that may reach Central KS late Sat Night. The projected track of the upper cyclone would likely cause the front to decelerate as it moves further southeast toward the turnpike. Thunderstorms would therefore increase with the greatest increase across Central KS Sat Night. Deep-layer shear remains fairly weak which would keep the severe potential marginal at best. With a very moist & unstable airmass entrenched across the neighborhood locally severe thunderstorms cannot be ruled out. At this time, the highest potential for severe thunderstorms would be across Central KS Sat Night & Sun where closer to the srn segment of the strong ewd-surging mid-upper wave. .LONG TERM...(Monday through Thursday) Issued at 328 AM CDT Fri Jun 24 2016 With the front, though weakening, stalled in an east/west manner across KS interacting with a very moist airmass thunderstorms would be expected for much of the upcoming work-week. Inherited forecast was kept intact. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1150 PM CDT Thu Jun 23 2016 VFR conditions are expected across the area for most locations overnight into Fri. SHRA/TSRA beginning to develop near KDDC at this time just ahead of a line of convection coming east off the high plains near KGCK. Low level moisture transport out of the OK panhandle is feeding this renewed convective development, with this convection expected to make its way east-southeast late tonight into early Fri morning. Propagation vectors suggests that the strongest convection will move more SE than E, which would suggest most of this renewed convection will drift south of the KRSL, KSLN and KGBD TAFS. Plan on keeping a VCTS for KHUT and KICT for the 08-12z time frame, as extrapolation of the convection may lead it to clipping South Central KS. Still uncertain on how strong the storms will be, but if they make it to KICT and KHUT then some MVFR vsbys or cigs may be possible. After the morning convection, expect VFR conditions to return the area for FRI afternoon as the frontal boundary begins to lift back north as a warm front. Ketcham && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 94 74 98 76 / 30 10 10 30 Hutchinson 95 74 99 74 / 30 10 10 40 Newton 93 73 97 75 / 30 10 10 30 ElDorado 93 73 95 75 / 30 10 10 30 Winfield-KWLD 94 74 96 77 / 30 10 10 20 Russell 95 74 99 70 / 20 20 40 60 Great Bend 96 74 99 70 / 20 20 30 60 Salina 95 75 100 73 / 20 10 20 50 McPherson 95 74 99 74 / 20 10 20 40 Coffeyville 92 72 94 75 / 30 10 10 10 Chanute 92 72 94 75 / 30 10 10 20 Iola 91 72 94 74 / 40 10 10 20 Parsons-KPPF 92 73 94 75 / 30 10 10 10 && .ICT Watches/Warnings/Advisories... None. && $$ SHORT TERM...EPS LONG TERM...EPS AVIATION...BDK
Area Forecast Discussion National Weather Service Goodland KS 1144 PM MDT THU JUN 23 2016 .SHORT TERM...(Today and tonight) Issued at 249 AM MDT Thu Jun 23 2016 Ongoing early morning convective activity continues eastward across southwest KS today along a frontal boundary that extends eastward into western Missouri and is laid up along the front range on the western side. Convective activity is expected to reinitiates later today along the front range and frontal boundary where moisture has pooled and the instability axis is located. Scattered storms will move east across the region overnight. The is currently a slight risk of severe storms over east central Colorado extending into west central Kansas. The main threat will be winds and large hail with some localized heavy rainfall possibly producing some flash flooding during the evening hours. The stronger westerly flow aloft remains well north of the forecast area, but several weaker short wave trough move east of the Rockies and across the central high plains through the short term period. These short waves are appearing as diurnally driven convective feedback features in the models as each of them seem to appear over the higher terrain late each afternoon and move east over the plains states during the afternoon and overnight hours as they weaken downstream. As a result, expect isolated to scattered late afternoon and evening thunderstorms to move across the forecast area again Friday and Saturday. Additionally a cold front will move across the central high plains region during the day on Saturday in advance of the upper low moving east of the northern Rockies and across the northern high plains in the vicinity of U.S./Canada border. This will provide a good focus for afternoon storms on Saturday. Temperatures are expected to be above normal with highs rising well into the 90s again on Friday, and backing off somewhat into the 80s and lower 90s again on Saturday with the passage of the cold front. .LONG TERM...(Friday night through Thursday) Issued at 307 PM MDT Thu Jun 23 2016 Forecast issues will be chances of precipitation through the period and high temperatures. Satellite showing an amplified flow across the Pacific to along the west coast of North America. The flow flattens out over the country with a broad ridge across the southern portion and lesser ridging/nearly zonal flow over the northern portion. Models differ with details on shortwave troughs through the Friday night through Sunday period. Models are suffering a lot from convective feedback and am thinking that they are overdoing the convection/qpf, especially from the end of Saturday night into Sunday. In cases would like to have made some specific periods dry but collaboration is keeping some kind of mention of thunderstorms in the forecast through the entire period. Friday night...Shortwave trough is near the western end of the later at beginning of the period with surface convergence near or just west. Problem is that 700 mb are plus 16 to 17. At this time will confine a slight chance to the far west initially. Expect thunderstorms to work their way east across the area as shortwave moves across. After midnight another shortwave trough moves at the same time the front moves through. This looks to either redevelop precipitation or keep it going through the rest of the night. Saturday/Saturday night...There looks to be ongoing thunderstorms in at the start of the morning. Question then becomes how much thunderstorm activity will be around in afternoon and night. Right rear quadrant of upper jet begins to affect the area in the afternoon and continues into the evening hours. However, you would think that the front and second shortwave should be pushing the moisture and thunderstorms out of the area by mid to late afternoon. At this time will keep something in the southeast half but am thinking the models are overdoing the qpf. Front will cool temperatures off about 5 to 10 degrees. Tended to go toward the slightly cooler guidance. Sunday...Was briefed that this period would be dry. However, a number of minor waves, some convectively induced, look to sporadically produce precipitation. Uncertainty and collaboration have kept some kind of pops in here. My gut feeling this day will be dry. Sunday night through Thursday...Model disagreement starts at the beginning of this period and gets worse with time. It involves the system moving from south central into eastern Canada and the resulting troughing over the eastern portion of the country. It also involves how the models handle the troughiness along the west coast. The handling or mishandling of these features affects the amplitude and the position of the western ridge. This ridge moves west with time and models typically have difficulty in retrogressing patterns. Models last week also had trouble with a similar setup. No matter which model you choose there looks to be numerous, hard time, shortwave troughs moving through in this flow. There looks to be waffling stationary boundary across the area during this time and because of the differences aloft, they differ on where they put this boundary. As a result the extended gave me slight chance to chance pops. Give the pattern, the uncertainty, and near impossibility of getting the details right at this time scale, have no problem in keeping those pops with only cosmetic changes. This period does have the potential to be active and wet. Also a result of the uncertainty, left the temperatures alone as well. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1144 PM MDT Thu Jun 23 2016 VFR conditions should continue through the TAF period. Isolated showers/thunderstorms may still be possible, however confidence that this would impact KGLD has greatly diminished and trends on radar have been towards current activity weakening before reaching KMCK. Fog/stratus may be possible in eastern Colorado by 12z, but confidence is low that this would reach KGLD and VFR conditions were prevailed. Winds should increase during the afternoon Friday before decreasing again around sunset. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...LOCKHART LONG TERM...BULLER AVIATION...DR
Area Forecast Discussion National Weather Service Goodland KS 1144 PM MDT THU JUN 23 2016 .SHORT TERM...(Today and tonight) Issued at 249 AM MDT Thu Jun 23 2016 Ongoing early morning convective activity continues eastward across southwest KS today along a frontal boundary that extends eastward into western Missouri and is laid up along the front range on the western side. Convective activity is expected to reinitiates later today along the front range and frontal boundary where moisture has pooled and the instability axis is located. Scattered storms will move east across the region overnight. The is currently a slight risk of severe storms over east central Colorado extending into west central Kansas. The main threat will be winds and large hail with some localized heavy rainfall possibly producing some flash flooding during the evening hours. The stronger westerly flow aloft remains well north of the forecast area, but several weaker short wave trough move east of the Rockies and across the central high plains through the short term period. These short waves are appearing as diurnally driven convective feedback features in the models as each of them seem to appear over the higher terrain late each afternoon and move east over the plains states during the afternoon and overnight hours as they weaken downstream. As a result, expect isolated to scattered late afternoon and evening thunderstorms to move across the forecast area again Friday and Saturday. Additionally a cold front will move across the central high plains region during the day on Saturday in advance of the upper low moving east of the northern Rockies and across the northern high plains in the vicinity of U.S./Canada border. This will provide a good focus for afternoon storms on Saturday. Temperatures are expected to be above normal with highs rising well into the 90s again on Friday, and backing off somewhat into the 80s and lower 90s again on Saturday with the passage of the cold front. .LONG TERM...(Friday night through Thursday) Issued at 307 PM MDT Thu Jun 23 2016 Forecast issues will be chances of precipitation through the period and high temperatures. Satellite showing an amplified flow across the Pacific to along the west coast of North America. The flow flattens out over the country with a broad ridge across the southern portion and lesser ridging/nearly zonal flow over the northern portion. Models differ with details on shortwave troughs through the Friday night through Sunday period. Models are suffering a lot from convective feedback and am thinking that they are overdoing the convection/qpf, especially from the end of Saturday night into Sunday. In cases would like to have made some specific periods dry but collaboration is keeping some kind of mention of thunderstorms in the forecast through the entire period. Friday night...Shortwave trough is near the western end of the later at beginning of the period with surface convergence near or just west. Problem is that 700 mb are plus 16 to 17. At this time will confine a slight chance to the far west initially. Expect thunderstorms to work their way east across the area as shortwave moves across. After midnight another shortwave trough moves at the same time the front moves through. This looks to either redevelop precipitation or keep it going through the rest of the night. Saturday/Saturday night...There looks to be ongoing thunderstorms in at the start of the morning. Question then becomes how much thunderstorm activity will be around in afternoon and night. Right rear quadrant of upper jet begins to affect the area in the afternoon and continues into the evening hours. However, you would think that the front and second shortwave should be pushing the moisture and thunderstorms out of the area by mid to late afternoon. At this time will keep something in the southeast half but am thinking the models are overdoing the qpf. Front will cool temperatures off about 5 to 10 degrees. Tended to go toward the slightly cooler guidance. Sunday...Was briefed that this period would be dry. However, a number of minor waves, some convectively induced, look to sporadically produce precipitation. Uncertainty and collaboration have kept some kind of pops in here. My gut feeling this day will be dry. Sunday night through Thursday...Model disagreement starts at the beginning of this period and gets worse with time. It involves the system moving from south central into eastern Canada and the resulting troughing over the eastern portion of the country. It also involves how the models handle the troughiness along the west coast. The handling or mishandling of these features affects the amplitude and the position of the western ridge. This ridge moves west with time and models typically have difficulty in retrogressing patterns. Models last week also had trouble with a similar setup. No matter which model you choose there looks to be numerous, hard time, shortwave troughs moving through in this flow. There looks to be waffling stationary boundary across the area during this time and because of the differences aloft, they differ on where they put this boundary. As a result the extended gave me slight chance to chance pops. Give the pattern, the uncertainty, and near impossibility of getting the details right at this time scale, have no problem in keeping those pops with only cosmetic changes. This period does have the potential to be active and wet. Also a result of the uncertainty, left the temperatures alone as well. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1144 PM MDT Thu Jun 23 2016 VFR conditions should continue through the TAF period. Isolated showers/thunderstorms may still be possible, however confidence that this would impact KGLD has greatly diminished and trends on radar have been towards current activity weakening before reaching KMCK. Fog/stratus may be possible in eastern Colorado by 12z, but confidence is low that this would reach KGLD and VFR conditions were prevailed. Winds should increase during the afternoon Friday before decreasing again around sunset. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...LOCKHART LONG TERM...BULLER AVIATION...DR
Area Forecast Discussion National Weather Service Wichita KS 1150 PM CDT THU JUN 23 2016 .UPDATE... Issued at 916 PM CDT Thu Jun 23 2016 Afternoon complex of storms is continuing to move to the east, with just some stratiform showers on the western edge still lingering across SE KS. Atmosphere in its wake across most of the forecast area, has stabilized. So expecting a lull in the convective chances for the rest of the evening hours. Still some concern for elevated convection to redevelop late tonight or storms currently over the high plains to drop east-southeast into western areas of the forecast area early Fri morning. Current hi-res solutions differ on how things will evolve early Fri morning. But latest RAP suggests low level moisture will increase from the OK panhandle into South Central KS after midnight. This moisture will overrun the stationary frontal boundary that remains draped across SRN KS. Highly conditional on if this moisture transport will be enough for storms to redevelop over South Central KS, or will it keep the high plains convection going east. Lots of uncertainty with either chance, but with the stationary front draped across the area will keep some low pops into Fri morning, in case either scenario leads to convection. Ketcham && .SHORT TERM...(This evening through Sunday night) Issued at 307 PM CDT Thu Jun 23 2016 Tonight into Friday: Residual frontal boundary, contaminated largely by outflow effects from the ongoing mcv-induced storm complex over south-central Kansas, extends eastward from southern Kansas into southern Missouri. Highest thunderstorm probabilities into early this evening, should exist underneath and just east of this eastward tracking mcv, with renewed convective development along the attendant outflow boundaries. Very strong instability, anomalously high precipitable water, steep low-level lapse rates exist in a west-east axis underneath the above features, with modest deep layer shear. Therefore, some of the stronger storm cores within multi-cell clusters will produce strong-severe wet downburst winds and torrential rainfall. Isolated diurnally-tied, nickel-quarter size hail is also a threat. There should be a brief lull this evening northwest of the KS Turnpike, with temporarily stabilized air behind the mcv storm complex. However, additional convection emanating from the higher terrain to the west within the monsoonal plume, should propagate eastward overnight into a weak southerly low-level jet. Storm chances should therefore increase again late tonight into the early morning hours in central and south-central Kansas. This activity would still be capable of strong downburst winds and torrential rainfall under the strongest cores or multi- cell clusters. Will maintain at least low chances of lingering convection in eastern Kansas Friday (mainly through midday), otherwise, return southerly flow and some sunshine will lead to a return to the heat and humidity for much of the area. It is possible that the heat advisory for extreme southeast KS near the Oklahoma border may be cancelled early, depending on how far east convective outlfow effects reach in the next few hours. Saturday through Sunday: A strong, somewhat compact upper trough will sweep eastward from the Northern Intermountain region, across the Northern Plains and Upper Mississippi Valley during this period. The associated cold front will slide southward into the Kansas region late Saturday, while weakening and stalling somehere across the state by Sunday, most likely in the south, while retaining its identity a bit more than the models suggest. Well-mixed breezy south-southwesterly boundary layer winds will allow very warm to hot conditions Saturday ahead of the front, with highs in the mid-upper 90s. Depending on how much the boundary layer dewpoints can lower, highs around 100 will be possible northwest of the Kansas Turnpike. With the upper ridge flattened, the monsoonal moist plume will stretch from the southern rockies eastward over Kansas near the front. Therefore, chances for at least scattered thunderstorms appear reasonable initially in Central Kansas late Saturday, potentially spreading into southern Kansas by Sunday. Although highs may trim back a few degrees Sunday with the front and storms in the region, readings will likely remain slightly above normal with rather humid air. .LONG TERM...(Monday through Thursday) Issued at 307 PM CDT Thu Jun 23 2016 The medium range models have been consistent in showing the upper ridge retrograding to the western states early next week, with longwave upper troughing over the eastern CONUS. This pattern will result in increased northwesterly flow aloft over the Central Plains. A lingering frontal zone across the Central Plains will serve as a focus for periodic thunderstorm chances, with upslope flow over the high plains and embedded upper disturbances in the northwest flow aloft serving as triggers for storms as well. The front is progged to meander slowly southward by Thursday, in part due to the embedded disturbances traversing the northwest flow aloft, and also from the outflow effects of storm complexes. As a result, slightly warmer than normal temperatures early in the week, are projected to fall back to slightly below normal by Thursday. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 1150 PM CDT Thu Jun 23 2016 VFR conditions are expected across the area for most locations overnight into Fri. SHRA/TSRA beginning to develop near KDDC at this time just ahead of a line of convection coming east off the high plains near KGCK. Low level moisture transport out of the OK panhandle is feeding this renewed convective development, with this convection expected to make its way east-southeast late tonight into early Fri morning. Propagation vectors suggests that the strongest convection will move more SE than E, which would suggest most of this renewed convection will drift south of the KRSL, KSLN and KGBD TAFS. Plan on keeping a VCTS for KHUT and KICT for the 08-12z time frame, as extrapolation of the convection may lead it to clipping South Central KS. Still uncertain on how strong the storms will be, but if they make it to KICT and KHUT then some MVFR vsbys or cigs may be possible. After the morning convection, expect VFR conditions to return the area for FRI afternoon as the frontal boundary begins to lift back north as a warm front. Ketcham && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 74 95 74 97 / 50 20 10 10 Hutchinson 70 95 74 97 / 50 20 10 10 Newton 71 94 74 96 / 50 30 10 10 ElDorado 73 94 74 95 / 50 30 10 10 Winfield-KWLD 74 95 74 96 / 40 20 10 10 Russell 70 96 74 97 / 50 20 20 40 Great Bend 70 96 74 97 / 50 20 20 30 Salina 71 96 75 97 / 40 30 10 20 McPherson 72 95 74 97 / 50 30 10 10 Coffeyville 72 93 73 94 / 80 20 10 10 Chanute 71 92 73 94 / 80 30 10 10 Iola 70 92 73 94 / 80 30 10 10 Parsons-KPPF 71 92 73 94 / 80 30 10 10 && .ICT Watches/Warnings/Advisories... None. && $$ UPDATE...Ketcham SHORT TERM...JMC LONG TERM...JMC AVIATION...BDK Area Forecast Discussion National Weather Service Flagstaff AZ 303 AM MST SUN JUN 26 2016 .SYNOPSIS...Dry and hot weather will persist across far western Arizona today. Mid level moisture will remain over central and eastern Arizona through Monday, and bring widely scattered showers and thunderstorms. Strong, gusty winds are possible near any storms. Monsoonal moisture to increase and spread across northern Arizona on Tuesday, with increasing daytime shower and thunderstorm activity lasting through the week. && .DISCUSSION... Northern Arizona will be slowly transitioning to a monsoon thunderstorm pattern over the next two days. Strong and gusty outflow winds should be expected near any storms or virga. The Flagstaff airport did have 2 periods of outflow wind gusts to 48 and 47 mph yesterday, an indication of outflow speeds possible through Monday afternoon. Satellite imagery this morning shows the monsoonal moisture plume running from NW Mexico through Tucson then northeastward through New Mexico. Satellite derived pw values are up to near 1.5 inches around Tuscon this morning. Models remain consistent in showing mid level easterly flow increasing across central and southern AZ today and this will allow moisture to slowly increase across areas along and south of I-40 through Monday. Areas along the Utah broder to remain hot and nearly cloud free today as this area is under the high pressure circulation center. Starting Tuesday, models are in good agreement with moist easterly flow through Wednesday morning becoming light southerly through Wednesday. Monsoonal moisture to remain overhead through the week and daytime precip chances were nudged upward a few points along the Mogollon Rim. Max temps to cool to near normal for dates starting Wednesday. && .AVIATION...For the 12Z Package...Isolated to scattered showers and thunderstorms will redevelop from KFLG-KRQE southeast after 18Z. The greatest aviation concern is storm outflow winds in excess of 40 kts. Otherwise, expect VFR conditions. Smoke downwind of active wildfires may impact local visibility. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Monsoon moisture will slowly increase northward each day. Expect deeper moisture with increasing coverage in showers and thunderstorms starting on Monday. Storm motion today and Monday will generally be from northeast to southwest. Expect erratic and gusty winds near any showers and storms. Tuesday through Thursday...An active wet Monsoon weather pattern is forecast with good shower and thunderstorm coverage each day across northern Arizona. .&& .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...DL AVIATION...MCS FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
  [top] Area Forecast Discussion National Weather Service Phoenix AZ 255 AM MST SUN JUN 26 2016 .SYNOPSIS... A very warm air mass will keep temperatures above normal through at least the first half of the week. A gradual increase in moisture will seep into portions of Arizona today and into the middle of the week, leading to a threat for showers and thunderstorms. Rainfall will initially be limited to the higher terrain, then finally move towards lower deserts as we move through the week. && .DISCUSSION... The monsoon has officially been underway since the middle of June, but for the most part convection has been minimal except for a few mountain storms east of Phoenix - most of the activity lately has been confined to the mountains of southeast Arizona. This will be changing in the very near future, and signs continue to point towards a gradual import of moisture westward and into the central Arizona deserts setting the stage for genuine desert monsoon thunderstorms. A look at recent plot, raob and satellite data showed the presence of an inverted trof moving westward and across southeast Arizona; at 2 am showers could be seen moving west across portions of Pima County associated with this feature. Latest Tucson sounding showed mid level flow now out of the southeast instead of west to southwest as was the case earlier in the week. Latest model guidance including mesoscale models such as the NMM6km indicate that the inverted trof will push west around the periphery of a building high pressure system, moving across far southern AZ and northwest Mexico today and tonight and as this occurs we can expect a few showers or thunderstorms over the lower central and southwest deserts during the day today. Despite the high building to our north, the increasing clouds and humidity will keep high temps over south central AZ below the 110 mark today, but drier air over the western deserts and into SE California will allow high temps today to climb to around 112 degrees - just slightly below excessive heat thresholds. Monday through Saturday... A more established monsoon, in terms of moisture, is expected over the southern half of AZ. The monsoon moisture boundary from southeast AZ is expected to move into the Phoenix area by Tuesday, then toward the lower Colorado River Valley by late Wednesday. In other words, most of our southwest and south-central AZ zones will be in the monsoon soup by the middle of the week, with enough potential energy for possible convective threats, although its really the little upper level nuances/perturbations that govern any larger outbreaks, and or colliding outflow boundaries which are difficult to discern this far in advance. Therefore, as far as convective threats are concerned for the week, we continue to feel that a broad brush approach to forecasting a slight chance of convective threats nearly everywhere is best. Another reason for the convective uncertainties involve the upper level nuances/perturbations. Models forecast one large 300/250 mb upper level inverted trof to move into southwest AZ from the northern Gulf of CA on Monday, with several follow-up smaller disturbances for the remainder of the week. Since the upper flow is very weak over northern Mexico, which inherently make the models less predictive or less reliable, and there are very few Mexican weather balloon soundings launched, we will take a wait and see position this far in advance before we jump on any one particular day next week that could be convectively significant. Again a broad brush slight chance of tstm approach is good for now, but hey, the monsoon will be here. By about Wednesday, precipitable water values will likely exceed 1.5 inches over much of the lower deserts from the lower Colorado River Valley eastward, and as the monsoon moisture corridor becomes better established, in addition to increasing thunderstorm coverage, the potential for heavy rainfall will become enhanced as well. Something else to look forward to later in the week. Of course, as the atmosphere becomes wetter/more humid, the high temperatures will trend downward and will likely drop below seasonal normals over portions of the central deserts by the middle or latter portion of the week. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Winds to remain on the light side, mainly aob 10 kts through Sunday, following typical diurnal trends, likely becoming easterly around midnight tonight, and westerly on Sunday afternoon. Scattered to broken mid-high cloud layers to linger into Sunday as a result of debris clouds from distant thunderstorms. There is once again an outside chance that outflows from distant thunderstorms could affect the terminals on Sun Aft/Eve, but confidence is too low to include it in the tafs at this time. Southeast California/Southwest Arizona including KIPL and KBLH: Skies will remain mostly clear over both TAF sites through Sunday. Winds will remain out of the south at KBLH and out of the south to southeast at KIPL, with speeds generally aob 10 kts accompanied by a few afternoon gusts up to 15 to 20 kts. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Tuesday through Saturday... Temperatures will be on a "cooling" trend, with highs on Tuesday around 108-115F dropping into the 102-110F range by Saturday. As monsoon moisture levels increase over the region, isolated thunderstorms are possible each afternoon/evening over much of the desert southwest, with the highest chances over the higher terrain of central and eastern Arizona. Accompanying any storm that develops will be wetting rains, gusty erratic winds, and lightning. This increase in moisture will support a rise in minimum humidities, with values ranging in the 15-25 percent range each day with good overnight recoveries. Outside of gusty storm winds, speeds will range between 5 to 15 mph with a few afternoon upslope gusts up to 20 mph. && .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...CB/Vasquez AVIATION...Percha FIRE WEATHER...Hernandez
  [top] Area Forecast Discussion National Weather Service Tucson AZ 858 PM MST SAT JUN 25 2016 .SYNOPSIS...We now have enough moisture for isolated to scattered showers and thunderstorms this weekend. A more favorable flow regime will then provide increased coverage of showers and thunderstorms Monday through Friday. && .DISCUSSION...Water vapor imagery shows a stark contrast between a dry mid level regime to our west and a moist airmass to the east. This line generally extends from Flagstaff to Phoenix to Organ Pipe National Monument. IR satellite imagery shows extensive mostly mid level debris clouds from earlier convection that covers most of my forecast area, with the exception of the far western portions of Pima county. Earlier this afternoon, isolated showers and storms developed over the Santa Catalina and Rincon mountains and eventually drifted off the mountains into the foothills with some gusty outflows and moderately heavy rainfall on the northeast portion of the Tucson metro and into the foothills. Several automated gauges reported amounts of 0.50 inches to around 0.80 inches. Currently, the radar mosaic from around the region indicates some light activity from remnants of earlier convection south of the border over eastern Santa Cruz and southwestern Cochise county and drifting west to northwest. Additional activity is occurring in southwestern New Mexico and drifting west, but this activity should continue to decrease through the remainder of the evening. Will keep a mention of a slight chance of showers and possible thunderstorms in the forecast overnight, mainly near the borders with Mexico and New Mexico. As of 03Z (8 PM MST), temperatures across the region ranged from the lower 70s near the international border, to the lower 90s over northern and central parts of the forecast area. The Tucson International Airport reported a temp of 89 degs after reaching an afternoon high of 100 degs. These readings seem to be on track with the inherited low temperature forecast, but will make some minor adjustments to the short term hourly temperature grids to reflect recent trends. See the previous discussion below for details beyond tonight. && .AVIATION...VALID THRU 27/06Z. Isolated to scattered -TSRA/-SHRA again Sunday afternoon. Cloud decks ranging from 10k- 15k ft msl. Gusty outflows possible with any storms that develop, otherwise surface wind will generally be less than 10 kts into Sunday. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect isolated to scattered showers and thunderstorms this weekend. Greater coverage of showers and thunderstorms should then occur Monday through next Friday. Otherwise, daytime minimum relative humidity values will generally range from the mid teens to around 30 percent with fair to good nighttime recovery. 20-foot winds this weekend as well as Wednesday through Friday will be terrain driven at less than 15 mph. 20-foot winds Monday and Tuesday will generally be from the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds Monday and Tuesday should prevail from shortly after sunrise into the early afternoon hours. && .PREV DISCUSSION...For Sunday, some secondary consolidation in the broad scale mean ridge position should tamp down convection with most favored locations being the central mountains and international border areas. Starting the day with what should still be a relatively weaker flow will make storms initially reluctant to push away from the mountains Sunday afternoon. However the UofA WRF-GFS is hinting at a couple of nice strong outflows pushing west and northwest late Sunday afternoon and early Sunday evening, filling in valley locations and probably generating dust north of Tucson. After that, as high pressure strengthens north of the area, the first half of the new week should see a better flow regime (albeit still on the weak side) for reinforcing deep moisture and importing one or two weaknesses in the flow. This should serve to anchor the entire week for seasonal convection. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ DISCUSSION...Mollere PREVIOUS DISCUSSION...Meyer/Rasmussen Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Phoenix AZ 850 PM MST SAT JUN 25 2016 .SYNOPSIS... A very warm air mass will keep temperatures above normal through at least the first half of next week. A gradual increase in moisture will seep into portions of Arizona later this weekend and into next week, leading to a threat for showers and thunderstorms. Rainfall will initially be limited to the higher terrain, then finally move towards lower deserts as we move into next week. && .DISCUSSION... A bit of an increase in convective activity today when compared to yesterday, but still very quiet at most locations. The main moisture plume, as seen on latest water vapor satellite imagery shifted a bit to the west today, allowing an increase in thunderstorm activity over the Tucson area, where areas on the northeast side of that city saw there 1st significant rainfall of the season, with some locations seeing up to 0.75 inch late this afternoon. A few storms also developed over the Rim Country, then tried to push southeastward into southern Gila county before dissipating. One cell did develop over the higher terrain north of US 60 between Superior and Globe earlier this evening, and likely did produce some brief heavy rainfall and gusty winds before dissipating. At this hour, all that is left from these storms is a weak outflow boundary that is now moving into northern Pinal/eastern Maricopa counties. The only likely impact from this outflow is will be to jsut produce a bit of gusty winds, up to 25 mph, which will likely not be strong enough to produce any significant blowing dust. Based on current trends and latest HRRR high-res forecasts, have reduced POPS somewhat and removed blowing dust from the grids for the remainder of this evening. As far as the forecast for Sunday is concerned, based on the latest NAM/GFS model output, is still looks like it will be very similar to today, and no further updates are planned. && .PREVIOUS DISCUSSION... Tonight and Sunday... Forecast for the next 7 days are going to be quite challenging with regards to thunderstorm threats as low/mid level moisture make a slow creep from southeast AZ this weekend, west into the remainder of the state throughout next week. However for tonight and Sunday, most of our forecast area will be dry with the exception of possible isolated thunderstorms over the mountains of southern Gila County this evening, and again Sunday evening. One thing that concerns us though, the models are forecasting a large mid level inverted trof to develop over northwest Mexico by late afternoon. We cant see it in the vapor imagery, however models insist that its resultant broad cyclonic circulation will rotate the bulk of convective debris clouds from southeast AZ, into central and southern AZ tonight and Sunday morning. This will mark the beginning of the slow westward moisture push. Unfortunately the Guaymas sounding in northwest Mexico along the Gulf coast has been missing for months now, so we cant get a close look at this evolving feature from measured data, and will have to default to the models and with their predictions of midlevel moisture advection through Sunday. Monday through Saturday... A more established monsoon, in terms of moisture, is expected over the southern half of AZ. The monsoon moisture boundary from southeast AZ is expected to move into the Phoenix area by Tuesday, then toward the lower Colorado River Valley by late Wednesday. In other words, most of our southwest and south-central AZ zones will be in the monsoon soup by the middle of next week, with enough potential energy for possible convective threats, although its really the little upper level nuances/perturbations that govern any larger outbreaks, and or colliding outflow boundaries which are difficult to discern this far in advance. Therefore, as far as convective threats are concerned for next week, we found that a broad brush approach to forecasting a slight chance of convective threats nearly everywhere was best. This approach actually started on the mid shift last night and accepted. Another reason for the convective uncertainties involve the upper level nuances/perturbations. Models forecast one large 300/250 mb upper level inverted trof to move into southwest AZ from the northern Gulf of CA on Monday, with several follow-up smaller disturbances for the remainder of the week. Since the upper flow is very weak over northern Mexico, which inherently make the models less predictive or less reliable, and there are very few Mexican weather balloon soundings launched, we will take a wait and see position this far in advance before we jump on any one particular day next week that could be convectively significant. Again a broad brush slight chance of tstm approach is good for now, but hey, the monsoon will be here. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Winds to remain on the light side, mainly aob 10 kts through Sunday, following typical diurnal trends, likely becoming easterly around midnight tonight, and westerly on Sunday afternoon. Scattered to broken mid-high cloud layers to linger into Sunday as a result of debris clouds from distant thunderstorms. There is once again an outside chance that outflows from distant thunderstorms could affect the terminals on Sun Aft/Eve, but confidence is too low to include it in the tafs at this time. Southeast California/Southwest Arizona including KIPL and KBLH: Skies will remain mostly clear over both TAF sites through Sunday. Winds will remain out of the south at KBLH and out of the south to southeast at KIPL, with speeds generally aob 10 kts accompanied by a few afternoon gusts up to 15 to 20 kts. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Tuesday through Saturday... Temperatures will be on a "cooling" trend, with highs on Tuesday around 108-115F dropping into the 102-110F range by Saturday. As monsoon moisture levels increase over the region, isolated thunderstorms are possible each afternoon/evening over much of the desert southwest, with the highest chances over the higher terrain of central and eastern Arizona. Accompanying any storm that develops will be wetting rains, gusty erratic winds, and lightning. This increase in moisture will support a rise in minimum humidities, with values ranging in the 15-25 percent range each day with good overnight recoveries. Outside of gusty storm winds, speeds will range between 5 to 15 mph with a few afternoon upslope gusts up to 20 mph. && .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/Vasquez AVIATION...Percha FIRE WEATHER...Hernandez
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
917 PM PDT SAT JUN 25 2016 .SYNOPSIS... Temperatures will increase during the fist half of the week as a ridge of high pressure builds over the Four Corners. Warmest conditions will be felt over the Inland Empire and deserts. A shallow marine layer will limit heating along the immediate coast. There is a very marginal chance for a light shower or isolated thunderstorm over the higher terrain Monday afternoon. Conditions will cool slightly later in the week as the ridge of high pressure weakens. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... At 900 PM a 500 MB ridge was positioned just off the CA coast, resulting in predominantly clear skies and light winds over SoCal. The lone exception was the immediate coast, where areas of marine layer low clouds were slowly reforming. Light onshore surface pressure gradients and a strong marine layer inversion, close to 23 degrees F on the 00z NKX sounding, will promote the continued development of a low stratus deck over the coast and western valleys overnight. Otherwise clear skies will persist for inland areas through Sunday morning. The 500 mb ridge currently off the CA coast will shift toward the Four Corners and strengthen to around 597 DM Monday and Tuesday. This will result in increasing temperatures inland, with the warmest conditions being felt over the Inland Empire and deserts. A Heat Advisory remains in effect for these areas Sunday afternoon through Wednesday evening to account for the warmer conditions. Aside from the heat, a weak easterly wave is forecast to propagate over Sonora Mexico late Sunday into Monday. This easterly wave should reach our region Monday afternoon, brining with it an increase in mid-level moisture. Mid-level clouds associated with this moisture may limit the afternoon heating some on Monday. There will also be a slight chance of a light shower or an isolated thunderstorm over the higher elevations Monday afternoon. The 500 mb ridge over the Four Corners will weaken late in the week, resulting in a slight cooling trend Wednesday into the weekend. Drier southwest flow will replace the easterly flow aloft, keeping the bulk of the monsoonal moisture to our east over AZ. && .AVIATION... 260400Z...Coast/Valleys...Stratus will be slower to spread along the coast tonight, with most coastal airports having BKN-OVC ceilings starting between 06Z and 09Z. Bases will be 1000-1400 feet MSL with tops to 1600 ft MSL. Stratus could spread up to 20 mi inland. Local vis below 3 mi will occur in the valleys 10Z-15Z. Clearing will occur 15Z-18Z Sunday, with areas of BKN-OVC stratus possibly continuing within 3 mi of the coast through 21Z Sunday. Patchy stratus with lower cloud bases will occur Sunday night. Confidence of forecast is moderate. Mountains/Deserts...Clear skies with unrestricted vis will continue through Sunday morning. && .MARINE... 900 PM...No hazardous marine weather is expected through Thursday. && .BEACHES... 900 PM...Nearshore buoys show 4-5 foot swell at 15 seconds, mostly from 200 degrees, with a very slight decrease from today. The south swell will gradually lower through Sunday. Although swell and surf will lower some Sunday, strong longshore and rips currents will continue to create hazardous swimming conditions through Sunday afternoon. A High Surf Advisory continues for the Orange County beaches through Sunday, and a Beach Hazard Statement is in effect for San Diego County for above average surf and strong rip currents. && .SKYWARN... Skywarn activation will not be needed today. && .SGX Watches/Warnings/Advisories... CA...Heat Advisory from noon Sunday to 8 PM PDT Wednesday for Apple and Lucerne Valleys-Coachella Valley-Riverside County Mountains-San Bernardino County Mountains-San Bernardino and Riverside County Valleys-The Inland Empire-San Diego County Deserts-San Diego County Mountains-San Gorgonio Pass Near Banning. Beach Hazards Statement through Sunday evening for San Diego County Coastal Areas. High Surf Advisory until 8 PM PDT Sunday for Orange County Coastal Areas. PZ...None. && $$ PUBLIC...Albright AVIATION/MARINE/BEACHES...Maxwell
Area Forecast Discussion National Weather Service San Francisco Bay Area 852 PM PDT SAT JUN 25 2016 .SYNOPSIS...High pressure will remain our dominant weather feature through the middle of next week, producing very warm and dry conditions inland. A shallow marine layer will persist near the coast along with light onshore flow. This will maintain seasonably cool weather in coastal areas. Cooling is expected in all areas late next week as a weak upper trough develops near the West Coast. && .DISCUSSION...As of 8:50 PM PDT Saturday...Skies were sunny across our entire region today as high pressure aloft strengthened over California. Most locations were anywhere from 3-9 degrees warmer today than yesterday. Inland valley locations warmed into the 90s. Meanwhile, a shallow marine layer and light onshore flow maintained seasonably cool conditions at the coast where highs were mostly in the 60s and 70s. The synoptic pattern is not forecast to change much over the next several days, so we can expect weather conditions through the middle of next week to be similar to what they were today. For the past few days there has not been sufficient moisture in the shallow marine layer to produce more than a few patches of night and morning low clouds near the coast. Based on the latest NAM and WRF model output, it is not likely we will see widespread low clouds and fog anytime soon, and what does develop will remain confined to areas close to the ocean. The medium range models agree that the upper ridge will weaken late in the week as a weak upper trough develops near the West Coast. This should result in at least modest cooling in all areas starting Thursday. && .AVIATION...As of 4:30 PM PDT Saturday...Surface high pressure over the Pacific Northwest is bringing a dry northerly flow to the area. Patchy low cigs will form overnight along the coast and MRY Bay otherwise clear VFR conditions expected. Vicinity of KSFO...VFR. Westerly winds 20-25 kt through 04z. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...IFR cigs after midnight. Confidence is not high due to the patchy nature of the clouds as it may stay VFR all night at MRY or SNS. && .MARINE...as of 10:35 AM PDT Saturday...Steep seas and locally strong northwest winds will continue across a majority of the coastal waters through early next week. A long period southerly swell will affect the waters through Saturday resulting in breaking waves at near shore reefs and sand bars. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pt Reyes to Pigeon Pt 0-10 nm SCA...Pigeon Pt to Pt Pinos 0-10 nm SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm SCA...Pt Arena to Pt Reyes 0-10 nm SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm SCA...SF Bay until 9 PM && $$ PUBLIC FORECAST: Dykema AVIATION: Larry MARINE: Larry Visit us at www.weather.gov/sanfrancisco Follow us on Facebook and twitter at: www.Facebook.com/nwsbayarea www.twitter.com/nwsbayarea
Area Forecast Discussion National Weather Service Phoenix AZ 850 PM MST SAT JUN 25 2016 .SYNOPSIS... A very warm air mass will keep temperatures above normal through at least the first half of next week. A gradual increase in moisture will seep into portions of Arizona later this weekend and into next week, leading to a threat for showers and thunderstorms. Rainfall will initially be limited to the higher terrain, then finally move towards lower deserts as we move into next week. && .DISCUSSION... A bit of an increase in convective activity today when compared to yesterday, but still very quiet at most locations. The main moisture plume, as seen on latest water vapor satellite imagery shifted a bit to the west today, allowing an increase in thunderstorm activity over the Tucson area, where areas on the northeast side of that city saw there 1st significant rainfall of the season, with some locations seeing up to 0.75 inch late this afternoon. A few storms also developed over the Rim Country, then tried to push southeastward into southern Gila county before dissipating. One cell did develop over the higher terrain north of US 60 between Superior and Globe earlier this evening, and likely did produce some brief heavy rainfall and gusty winds before dissipating. At this hour, all that is left from these storms is a weak outflow boundary that is now moving into northern Pinal/eastern Maricopa counties. The only likely impact from this outflow is will be to jsut produce a bit of gusty winds, up to 25 mph, which will likely not be strong enough to produce any significant blowing dust. Based on current trends and latest HRRR high-res forecasts, have reduced POPS somewhat and removed blowing dust from the grids for the remainder of this evening. As far as the forecast for Sunday is concerned, based on the latest NAM/GFS model output, is still looks like it will be very similar to today, and no further updates are planned. && .PREVIOUS DISCUSSION... Tonight and Sunday... Forecast for the next 7 days are going to be quite challenging with regards to thunderstorm threats as low/mid level moisture make a slow creep from southeast AZ this weekend, west into the remainder of the state throughout next week. However for tonight and Sunday, most of our forecast area will be dry with the exception of possible isolated thunderstorms over the mountains of southern Gila County this evening, and again Sunday evening. One thing that concerns us though, the models are forecasting a large mid level inverted trof to develop over northwest Mexico by late afternoon. We cant see it in the vapor imagery, however models insist that its resultant broad cyclonic circulation will rotate the bulk of convective debris clouds from southeast AZ, into central and southern AZ tonight and Sunday morning. This will mark the beginning of the slow westward moisture push. Unfortunately the Guaymas sounding in northwest Mexico along the Gulf coast has been missing for months now, so we cant get a close look at this evolving feature from measured data, and will have to default to the models and with their predictions of midlevel moisture advection through Sunday. Monday through Saturday... A more established monsoon, in terms of moisture, is expected over the southern half of AZ. The monsoon moisture boundary from southeast AZ is expected to move into the Phoenix area by Tuesday, then toward the lower Colorado River Valley by late Wednesday. In other words, most of our southwest and south-central AZ zones will be in the monsoon soup by the middle of next week, with enough potential energy for possible convective threats, although its really the little upper level nuances/perturbations that govern any larger outbreaks, and or colliding outflow boundaries which are difficult to discern this far in advance. Therefore, as far as convective threats are concerned for next week, we found that a broad brush approach to forecasting a slight chance of convective threats nearly everywhere was best. This approach actually started on the mid shift last night and accepted. Another reason for the convective uncertainties involve the upper level nuances/perturbations. Models forecast one large 300/250 mb upper level inverted trof to move into southwest AZ from the northern Gulf of CA on Monday, with several follow-up smaller disturbances for the remainder of the week. Since the upper flow is very weak over northern Mexico, which inherently make the models less predictive or less reliable, and there are very few Mexican weather balloon soundings launched, we will take a wait and see position this far in advance before we jump on any one particular day next week that could be convectively significant. Again a broad brush slight chance of tstm approach is good for now, but hey, the monsoon will be here. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Winds to remain on the light side, mainly aob 10 kts through Sunday, following typical diurnal trends, likely becoming easterly around midnight tonight, and westerly on Sunday afternoon. Scattered to broken mid-high cloud layers to linger into Sunday as a result of debris clouds from distant thunderstorms. There is once again an outside chance that outflows from distant thunderstorms could affect the terminals on Sun Aft/Eve, but confidence is too low to include it in the tafs at this time. Southeast California/Southwest Arizona including KIPL and KBLH: Skies will remain mostly clear over both TAF sites through Sunday. Winds will remain out of the south at KBLH and out of the south to southeast at KIPL, with speeds generally aob 10 kts accompanied by a few afternoon gusts up to 15 to 20 kts. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Tuesday through Saturday... Temperatures will be on a "cooling" trend, with highs on Tuesday around 108-115F dropping into the 102-110F range by Saturday. As monsoon moisture levels increase over the region, isolated thunderstorms are possible each afternoon/evening over much of the desert southwest, with the highest chances over the higher terrain of central and eastern Arizona. Accompanying any storm that develops will be wetting rains, gusty erratic winds, and lightning. This increase in moisture will support a rise in minimum humidities, with values ranging in the 15-25 percent range each day with good overnight recoveries. Outside of gusty storm winds, speeds will range between 5 to 15 mph with a few afternoon upslope gusts up to 20 mph. && .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/Vasquez AVIATION...Percha FIRE WEATHER...Hernandez Area Forecast Discussion National Weather Service Phoenix AZ 815 AM SUN JUN 26 2016 .SYNOPSIS... A very warm air mass will keep temperatures above normal through at least the first half of the week. A gradual increase in moisture will seep into portions of Arizona today and into the middle of the week, leading to a threat for showers and thunderstorms. Rainfall will initially be limited to the higher terrain, then finally move towards lower deserts as we move through the week. && .DISCUSSION... Regional upper air data showed the monsoon moisture boundary (MMB) in southeast AZ was deeper than yesterday, and had shifted slightly west and northwest since yesterday morning. In other words, the MMB was between Phoenix and Tucson, or the leading edge of the deepest moisture normally associated with a monsoon airmass extended from the White Mountains in far east central AZ, southwestward to between Phoenix and Tucson, then over to Ajo. And there was another twist in this mornings complicated upper level 300/250 mb flow pattern, something totally unexpected this morning. Yesterday at this time the models were forecasting a growing inverted trof over northwest Mexico southwest of Tucson. We didnt see its circulation in the mostly reliable water vapor imagery (WVI) yesterday , but this morning it was obviouse in the WVI. However the surprise is, the models are moving this feature north into AZ 24 hours ahead of schedule. In fact, the southwest/northeast orientated cloud band over southern AZ is the leading edge of the 300/250 mb deformation zone, forecast to shift northwestward throughout the day. Again this is a whole 24 hours ahead of schedule. Like we said yesterday, forecasting upper level features in a typical light wind pattern of a subtropical airmass can give us fits, even in the short term. OK what does it all mean for our forecast area. With light east southeasterly winds developing in a deep boundary layer, monsooon moisture will continue to spread slowly west and north today. The upper level inverted trof will continue to move north into AZ and provide weak upper level support to any convective activity, first over the mountains then later onto the deserts. Perhaps the best threat for the greater Phoenix area will be gusty former tstm outflow winds and blowing dust than a direct tstm hit. Any desert convective threats will likely favor the Casa Grande, Gila Bend, and west toward eastern Yuma County areas. The mid shift made adjustments to precip probability coverage on the lower deserts due to the inverted trof, and accepted. Otherwise no short term updates are expected. .PREVIOUS DISCUSSION...452 AM MST... The monsoon has officially been underway since the middle of June, but for the most part convection has been minimal except for a few mountain storms east of Phoenix - most of the activity lately has been confined to the mountains of southeast Arizona. This will be changing in the very near future, and signs continue to point towards a gradual import of moisture westward and into the central Arizona deserts setting the stage for genuine desert monsoon thunderstorms. A look at recent plot, raob and satellite data showed the presence of an inverted trof moving westward and across southeast Arizona; at 2 am showers could be seen moving west across portions of Pima County associated with this feature. Latest Tucson sounding showed mid level flow now out of the southeast instead of west to southwest as was the case earlier in the week. Latest model guidance including mesoscale models such as the NMM6km indicate that the inverted trof will push west around the periphery of a building high pressure system, moving across far southern AZ and northwest Mexico today and tonight and as this occurs we can expect a few showers or thunderstorms over the lower central and southwest deserts during the day today. Despite the high building to our north, the increasing clouds and humidity will keep high temps over south central AZ below the 110 mark today, but drier air over the western deserts and into SE California will allow high temps today to climb to around 112 degrees - just slightly below excessive heat thresholds. Monday through Saturday... A more established monsoon, in terms of moisture, is expected over the southern half of AZ. The monsoon moisture boundary from southeast AZ is expected to move into the Phoenix area by Tuesday, then toward the lower Colorado River Valley by late Wednesday. In other words, most of our southwest and south-central AZ zones will be in the monsoon soup by the middle of the week, with enough potential energy for possible convective threats, although its really the little upper level nuances/perturbations that govern any larger outbreaks, and or colliding outflow boundaries which are difficult to discern this far in advance. Therefore, as far as convective threats are concerned for the week, we continue to feel that a broad brush approach to forecasting a slight chance of convective threats nearly everywhere is best. Another reason for the convective uncertainties involve the upper level nuances/perturbations. Models forecast one large 300/250 mb upper level inverted trof to move into southwest AZ from the northern Gulf of CA on Monday, with several follow-up smaller disturbances for the remainder of the week. Since the upper flow is very weak over northern Mexico, which inherently make the models less predictive or less reliable, and there are very few Mexican weather balloon soundings launched, we will take a wait and see position this far in advance before we jump on any one particular day next week that could be convectively significant. Again a broad brush slight chance of tstm approach is good for now, but hey, the monsoon will be here. By about Wednesday, precipitable water values will likely exceed 1.5 inches over much of the lower deserts from the lower Colorado River Valley eastward, and as the monsoon moisture corridor becomes better established, in addition to increasing thunderstorm coverage, the potential for heavy rainfall will become enhanced as well. Something else to look forward to later in the week. Of course, as the atmosphere becomes wetter/more humid, the high temperatures will trend downward and will likely drop below seasonal normals over portions of the central deserts by the middle or latter portion of the week. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Mostly light winds following typical diurnal trends for the Phoenix terminals through tonight. Scattered to broken mid-high clouds to persist through much of the period. Isolated showers and thunderstorms should mostly stay over higher terrain, but there is an outside chance of a few making it into the lower deserts. Storm outflows remain more likely from distant thunderstorms and could affect the terminals this evening, but confidence is too low to include it in the tafs. Southeast California/Southwest Arizona including KIPL and KBLH: Clear skies this morning will give way to few to sct mid clouds by noon. May see a few virga showers across southwest Arizona, but should not affect area terminals. Winds will remain out of the south at KBLH and out of the south to southeast at KIPL, with speeds generally aob 10 kts accompanied by a few afternoon gusts up to 15 to 20 kts. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Tuesday through Saturday... Temperatures will be on a "cooling" trend, with highs on Tuesday around 108-115F dropping into the 102-110F range by Saturday. As monsoon moisture levels increase over the region, isolated thunderstorms are possible each afternoon/evening over much of the desert southwest, with the highest chances over the higher terrain of central and eastern Arizona. Accompanying any storm that develops will be wetting rains, gusty erratic winds, and lightning. This increase in moisture will support a rise in minimum humidities, with values ranging in the 15-25 percent range each day with good overnight recoveries. Outside of gusty storm winds, speeds will range between 5 to 15 mph with a few afternoon upslope gusts up to 20 mph. && .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...Vasquez AVIATION...Kuhlman FIRE WEATHER...Hernandez
Area Forecast Discussion National Weather Service Phoenix AZ 452 AM MST SUN JUN 26 2016 .UPDATE...Updated aviation discussion... && .SYNOPSIS... A very warm air mass will keep temperatures above normal through at least the first half of the week. A gradual increase in moisture will seep into portions of Arizona today and into the middle of the week, leading to a threat for showers and thunderstorms. Rainfall will initially be limited to the higher terrain, then finally move towards lower deserts as we move through the week. && .DISCUSSION... The monsoon has officially been underway since the middle of June, but for the most part convection has been minimal except for a few mountain storms east of Phoenix - most of the activity lately has been confined to the mountains of southeast Arizona. This will be changing in the very near future, and signs continue to point towards a gradual import of moisture westward and into the central Arizona deserts setting the stage for genuine desert monsoon thunderstorms. A look at recent plot, raob and satellite data showed the presence of an inverted trof moving westward and across southeast Arizona; at 2 am showers could be seen moving west across portions of Pima County associated with this feature. Latest Tucson sounding showed mid level flow now out of the southeast instead of west to southwest as was the case earlier in the week. Latest model guidance including mesoscale models such as the NMM6km indicate that the inverted trof will push west around the periphery of a building high pressure system, moving across far southern AZ and northwest Mexico today and tonight and as this occurs we can expect a few showers or thunderstorms over the lower central and southwest deserts during the day today. Despite the high building to our north, the increasing clouds and humidity will keep high temps over south central AZ below the 110 mark today, but drier air over the western deserts and into SE California will allow high temps today to climb to around 112 degrees - just slightly below excessive heat thresholds. Monday through Saturday... A more established monsoon, in terms of moisture, is expected over the southern half of AZ. The monsoon moisture boundary from southeast AZ is expected to move into the Phoenix area by Tuesday, then toward the lower Colorado River Valley by late Wednesday. In other words, most of our southwest and south-central AZ zones will be in the monsoon soup by the middle of the week, with enough potential energy for possible convective threats, although its really the little upper level nuances/perturbations that govern any larger outbreaks, and or colliding outflow boundaries which are difficult to discern this far in advance. Therefore, as far as convective threats are concerned for the week, we continue to feel that a broad brush approach to forecasting a slight chance of convective threats nearly everywhere is best. Another reason for the convective uncertainties involve the upper level nuances/perturbations. Models forecast one large 300/250 mb upper level inverted trof to move into southwest AZ from the northern Gulf of CA on Monday, with several follow-up smaller disturbances for the remainder of the week. Since the upper flow is very weak over northern Mexico, which inherently make the models less predictive or less reliable, and there are very few Mexican weather balloon soundings launched, we will take a wait and see position this far in advance before we jump on any one particular day next week that could be convectively significant. Again a broad brush slight chance of tstm approach is good for now, but hey, the monsoon will be here. By about Wednesday, precipitable water values will likely exceed 1.5 inches over much of the lower deserts from the lower Colorado River Valley eastward, and as the monsoon moisture corridor becomes better established, in addition to increasing thunderstorm coverage, the potential for heavy rainfall will become enhanced as well. Something else to look forward to later in the week. Of course, as the atmosphere becomes wetter/more humid, the high temperatures will trend downward and will likely drop below seasonal normals over portions of the central deserts by the middle or latter portion of the week. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Mostly light winds following typical diurnal trends for the Phoenix terminals through tonight. Scattered to broken mid-high clouds to persist through much of the period. Isolated showers and thunderstorms should mostly stay over higher terrain, but there is an outside chance of a few making it into the lower deserts. Storm outflows remain more likely from distant thunderstorms and could affect the terminals this evening, but confidence is too low to include it in the tafs. Southeast California/Southwest Arizona including KIPL and KBLH: Clear skies this morning will give way to few to sct mid clouds by noon. May see a few virga showers across southwest Arizona, but should not affect area terminals. Winds will remain out of the south at KBLH and out of the south to southeast at KIPL, with speeds generally aob 10 kts accompanied by a few afternoon gusts up to 15 to 20 kts. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Tuesday through Saturday... Temperatures will be on a "cooling" trend, with highs on Tuesday around 108-115F dropping into the 102-110F range by Saturday. As monsoon moisture levels increase over the region, isolated thunderstorms are possible each afternoon/evening over much of the desert southwest, with the highest chances over the higher terrain of central and eastern Arizona. Accompanying any storm that develops will be wetting rains, gusty erratic winds, and lightning. This increase in moisture will support a rise in minimum humidities, with values ranging in the 15-25 percent range each day with good overnight recoveries. Outside of gusty storm winds, speeds will range between 5 to 15 mph with a few afternoon upslope gusts up to 20 mph. && .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...CB/Vasquez AVIATION...Kuhlman FIRE WEATHER...Hernandez
  [top] Area Forecast Discussion National Weather Service Tucson AZ 405 AM MST SAT JUN 25 2016 .SYNOPSIS...We now have enough moisture for isolated to scattered showers and thunderstorms this weekend. A more favorable flow regime will then provide increased coverage of showers and thunderstorms Monday through next Saturday. && .DISCUSSION...IR satellite imagery and surface observations depicted mostly cloudy to cloudy skies across southeast Arizona early this morning. KEMX WSR-88D detected isolated to scattered showers producing mainly sprinkles from southwestern Cochise County westward into western Pima County. The 25/06Z Univ of AZ WRF-NAM and several HRRR solutions suggest that mostly cloudy skies to cloudy skies will continue thru at least mid-morning, and sprinkles to perhaps just a few hundredths of an inch of rain should also prevail mostly west-to-south of Tucson. These high resolution models then depict clearing skies from south- to-north late this morning. The clearing skies will set the stage for isolated to scattered showers and thunderstorms to develop by early this afternoon southwest-to-southeast of Tucson. These showers and thunderstorms should then move northwestward during the late afternoon/early evening hours. Have noted that the 25/06Z U/A WRF-NAM depicts a marked downtrend in intensity of precip echoes early this evening. Assuming this scenario to be reality, the potential for significant blowing dust in the favorable dust-prone I-10 corridor from Tucson to Phoenix would be mitigated. For this forecast package, have opted to depict patchy blowing dust late this afternoon and early evening from the far northwest Tucson metro area northwestward into south central Pinal County and the northern portion of the Tohono O`Odham Nation. Have also maintained isolated showers/tstms late tonight mainly east of Tucson. The hi-res models suggest a scenario late tonight similar to that presently occurring across the area. In other words, a fairly widespread convective debris cloud cover with patches of sprinkles or light rain. 26/00Z GFS/ECMWF/CMC remained fairly similar regarding the synoptic scale pattern regime over the southwestern states starting Monday and continuing into early next weekend. Strong high pressure aloft Monday is progged to become centered over southern Utah. The GFS/ ECMWF depict an inverted trough to move into southwestern AZ from the northern Gulf of California Monday. Quick glance at the U/A WRF-NAM suggests that showers/tstms Monday afternoon would only be confined to the White Mountains and near the international border adjacent Santa Cruz/southern Pima County. Thus, there is the potential that Monday may be a "down day" perhaps due to subsidence on the eastern periphery of the aforementioned inverted trough. Forecast confidence in this particular detail is somewhat low, however. Thus, for this forecast package, have continued with scattered showers/tstms mainly from Tucson eastward/southward. Thereafter, not much daily variation in shower/tstm coverage is anticipated Tuesday into next Saturday. The deterministic GFS/ECMWF/ CMC were similar with maintaining fairly ample moisture across this forecast area. These solutions were similar with the continuation of a light ely/sely mid-level flow regime thru about Wednesday. The mid- level flow regime is then progged to become more wly/swly especially from Tucson westward starting Thursday and continuing into next Saturday. This subtle change may be sufficient for at least a slight downward trend in shower/tstm coverage, especially across western sections. Again, forecast confidence is fairly low at this time in stating that a definitive downward precip trend anywhere in the area is in the offing late this week. High temps for the Tucson metro area and locales west-to-northwest of Tucson will be near normal during much of this forecast period. However, daytime temps for locales east-to-south of Tucson, such as Safford, Douglas and Nogales will average a few degs below normal this week. && .AVIATION...VALID THRU 27/12Z. Isolated -SHRA especially west-to-south of KTUS thru about 15Z-17Z this morning, then isolated to scattered -TSRA/-SHRA this afternoon and evening. The best chance of -TSRA/-SHRA will occur from KTUS vicinity eastward/southward to the New Mexico/international borders. The best timing for TSRA at the KTUS/KOLS/KDUG terminals is mostly from 20Z this afternoon until 27/02Z this evening. Brief wind gusts to near 40 kts and MVFR conditions due to reduced visibilities will be possible with the stronger TSRA. Isolated -SHRA/-TSRA will be possible area-wide late tonight into early Monday morning. Otherwise, cloud decks generally ranging from 10k-15k ft msl, and surface wind terrain driven mainly less than 12 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect isolated to scattered showers and thunderstorms this afternoon and evening. Greater coverage of showers and thunderstorms should then occur Monday through next Saturday. Otherwise, daytime minimum relative humidity values will generally range from the mid teens to around 30 percent with fair to good nighttime recovery. 20-foot winds into Monday as well as Thursday through Saturday will be terrain driven at less than 15 mph. 20-foot winds Tuesday and Wednesday will generally be from the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds Tuesday and Wednesday should prevail from shortly after sunrise into the early afternoon hours. && .PREV DISCUSSION...For Sunday, some secondary consolidation in the broad scale mean ridge position should tamp down convection with most favored locations being the central mountains and international border areas. Starting the day with what should still be a relatively weaker flow will make storms initially reluctant to push away from the mountains Sunday afternoon. However the UofA WRF-GFS is hinting at a couple of nice strong outflows pushing west and northwest late Sunday afternoon and early Sunday evening, filling in valley locations and probably generating dust north of Tucson. After that, as high pressure strengthens north of the area, the first half of the new week should see a better flow regime (albeit still on the weak side) for reinforcing deep moisture and importing one or two weaknesses in the flow. This should serve to anchor the entire week for seasonal convection. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Francis Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson Area Forecast Discussion National Weather Service Tucson AZ 336 PM MST SUN JUN 26 2016 .SYNOPSIS...Plenty of moisture around this week with an increasing chance of mainly afternoon and evening showers and thunders across Southeast Arizona. && DISCUSSION...Convection is finally firing over expected areas, including areas southeast through southwest of Tucson as well as the east central mountains (northern Graham and Greenlee counties). We had a delays in initiation due to morning cloud cover as well as a bit more convective inhibition to overcome as per the KTWC morning sounding. So the strong outflow from the southern Mogollon Rim is just now pushing southwest into valley locations of Graham county, and it doesn`t really look as strong as the increasing mid level easterly flow suggested earlier. Development across southern areas is increasing, but not anything to write home about either. We may still have some mid level CAPE for an outflow to tap into later this evening, so more debris to contend with early Monday morning. Weak subsidence behind a minor mid level feature shifting north of the area will probably limit thunderstorms to mainly mountain areas Monday. A deeper and stronger fetch around high pressure reconsolidating to our east should push our thunderstorm coverage up as we reinforce available moisture and draw in weak inflections around the high. && AVIATION...VALID THRU 28/00Z. Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is mostly from 20Z this afternoon until 27/08Z this evening. Brief wind gusts to near 40 kts and MVFR conditions due to reduced visibilities will be possible with the stronger TSRA. Isolated -SHRA/-TSRA will be possible area-wide late tonight into early Monday afternoon. Otherwise, cloud decks generally ranging from 10k- 15k ft MSL, and surface wind terrain driven mainly less than 12 kts. Aviation discussion not updated for TAF amendments. && FIRE WEATHER...Expect isolated to scattered showers and thunderstorms this afternoon and evening. Greater coverage of showers and thunderstorms should then occur Monday through next Saturday. Otherwise, daytime minimum relative humidity values will generally range from the mid teens to around 30 percent with fair to good nighttime recovery. 20-foot winds into Monday as well as Thursday through Saturday will be terrain driven at less than 15 mph. 20-foot winds Tuesday and Wednesday will generally be from the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds Tuesday and Wednesday should prevail from shortly after sunrise into the early afternoon hours. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Meyer/Rasmussen Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Tucson AZ 336 PM MST SUN JUN 26 2016 .SYNOPSIS...Plenty of moisture around this week with an increasing chance of mainly afternoon and evening showers and thunders across Southeast Arizona. && DISCUSSION...Convection is finally firing over expected areas, including areas southeast through southwest of Tucson as well as the east central mountains (northern Graham and Greenlee counties). We had a delays in initiation due to morning cloud cover as well as a bit more convective inhibition to overcome as per the KTWC morning sounding. So the strong outflow from the southern Mogollon Rim is just now pushing southwest into valley locations of Graham county, and it doesn`t really look as strong as the increasing mid level easterly flow suggested earlier. Development across southern areas is increasing, but not anything to write home about either. We may still have some mid level CAPE for an outflow to tap into later this evening, so more debris to contend with early Monday morning. Weak subsidence behind a minor mid level feature shifting north of the area will probably limit thunderstorms to mainly mountain areas Monday. A deeper and stronger fetch around high pressure reconsolidating to our east should push our thunderstorm coverage up as we reinforce available moisture and draw in weak inflections around the high. && AVIATION...VALID THRU 28/00Z. Isolated to scattered -TSRA/-SHRA. The best timing for TSRA is mostly from 20Z this afternoon until 27/08Z this evening. Brief wind gusts to near 40 kts and MVFR conditions due to reduced visibilities will be possible with the stronger TSRA. Isolated -SHRA/-TSRA will be possible area-wide late tonight into early Monday afternoon. Otherwise, cloud decks generally ranging from 10k- 15k ft MSL, and surface wind terrain driven mainly less than 12 kts. Aviation discussion not updated for TAF amendments. && FIRE WEATHER...Expect isolated to scattered showers and thunderstorms this afternoon and evening. Greater coverage of showers and thunderstorms should then occur Monday through next Saturday. Otherwise, daytime minimum relative humidity values will generally range from the mid teens to around 30 percent with fair to good nighttime recovery. 20-foot winds into Monday as well as Thursday through Saturday will be terrain driven at less than 15 mph. 20-foot winds Tuesday and Wednesday will generally be from the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds Tuesday and Wednesday should prevail from shortly after sunrise into the early afternoon hours. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Meyer/Rasmussen Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
  [top] Area Forecast Discussion National Weather Service Phoenix AZ 240 PM SUN JUN 26 2016 .SYNOPSIS... A very warm air mass will keep temperatures above normal through at least the first half of the week. A increase in monsoon moisture is also expected, and will provide a slight threat of afternoon and evening showers and thunderstorms the remainder of week. && .DISCUSSION... Tonight... The inverted trof so noticeable on vapor imagery just south of the AZ border developed an west-east deformation/stretching zone replete with considerable mid/high level cloudiness. Cloudiness was able to retard the heating curve and defer any precip to virga or light showers with the dense clouds. More is expected overnight. However there are a few afternoon thunderstorms in the less cloudy areas of the White Mountains, just west of Nogales along the Mexican border, and in far southeast AZ at 2 pm mst. Monday through Saturday The forecast becomes very complicated this week with respect to shower/thunderstorm potential, coverage, and intensity, mainly across portions of southwest and south central AZ. In other words, can we call it quasi-unsettled this week? We know the monsoon moisture boundary arrived in southeast AZ the past couple of days, and is forecast to spread west and north across the remainder of southern and central AZ this week. And, normally this time of year once the moistures in place it should be like clock-work right, i.e., first afternoon mountain thunderstorms then by evening drifting toward the desert edge, including developing on convective outflows and/or outflow collisions. Not this week, there is too much going on in the mid and upper atmosphere. For example, the last vestiges of the northwest Mexico inverted trof will move into the region Monday afternoon. More cyclonicity over southern CA will develop a threat of thunderstorms over the Joshua Tree National Park mountains, while difluent flow aloft in southwest and south central AZ generates convective potential as well. But a caveat, extensive mid/high clouds associated with the inverted trof axis may cut down on afternoon heating and the convective potential in the south central AZ Monday. And for Tuesday and Tuesday night, while 300/250 mb flows become southwesterly, a developing 500 mb easterly flow advects a weak mid level disturbance from New Mexico into southeast and south Central AZ late Tuesday afternoon and night. 500 mb disturbances usually spark overnight convection under very moist conditions. Therefore there is much uncertainty, and we can go on and on for Wednesday through Saturday. Therefore the best approach is to call is quasi-unsettled, or a broad brush approach to shower/thunderstorm potential since 1) the monsoon moisture will be in place, and 2) models will no doubt have trouble forecasting any minor perturbations in this developing convoluted flow aloft. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: Showers moving in from the southeast have caused winds to shift to a southeasterly direction this afternoon over Phoenix terminals. With more activity in southeast AZ still propagating to the northwest, anticipate that these southeasterly winds will stick around for another hour or so before shifting temporarily back to the west around 22Z. Speeds will remain around 10 kts, however cannot rule out gusty erratic winds and blowing dust from distant south and east AZ storms for the remainder of the day at Phoenix terminals. However, low confidence in exact spatial and temporal coverage precludes mention in 18Z TAF. Broken to overcast mid to high clouds aoa 10kft will continue to advect into the region for the remainder of the day before decreasing in coverage early tomorrow morning. Southeast California/Southwest Arizona including KIPL and KBLH: Skies will remain mostly clear with a few passing high clouds around 15-20 kft. Winds will remain out of the south at KBLH and out of the southeast at KIPL, with speeds generally around 10-15 kts accompanied by a few afternoon gusts up to 20 to 25 kts. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Wednesday through Sunday... Temperatures will continue to "cool," with highs on Wednesday around 105-112F dropping into the 100-110F range by Sunday. As monsoon moisture levels continue to increase over the region, isolated thunderstorms are possible each afternoon/evening over much of the desert southwest, with the highest chances over the higher terrain of central and eastern Arizona. Accompanying any storm that develops will be wetting rains, gusty erratic winds, and lightning. This increase in moisture will support a rise in minimum humidities, with values ranging in the 15-25 percent range each day with good overnight recoveries. Outside of gusty storm winds, speeds will range between 5 to 15 mph with a few afternoon upslope gusts up to 20 mph. && .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...Vasquez AVIATION...Hernandez FIRE WEATHER...Hernandez
  [top] Area Forecast Discussion National Weather Service Flagstaff AZ 940 AM MST SUN JUN 26 2016 .SYNOPSIS...Dry and hot weather will persist across far western Arizona today. Mid level moisture will remain over central and eastern Arizona through Monday, and bring widely scattered showers and thunderstorms. Strong, gusty winds are possible near any storms. Monsoonal moisture to increase and spread across northern Arizona on Tuesday, with increasing daytime shower and thunderstorm activity lasting through the week. && .DISCUSSION...For today, the highest moisture and best chances for showers and thunderstorms will be along and south of the White Mountains and the eastern Mogollon Rim. Elsewhere, drier air and more stable conditions will limit convective activity. Slight chances for showers are forecast along the western Mogollon Rim, including the city of Flagstaff. This seems reasonable as an extensive cumulus field is expected to develop with heating. As highlighted in the previous forecast discussion, today`s storms will once again be high-based leading to the potential for strong outflows from collapsing storms. In terms of forecast updates, the current forecast appears to be on track and no short term updates are anticipated at this time. && .PREV DISCUSSION /303 AM MST/... Northern Arizona will be slowly transitioning to a monsoon thunderstorm pattern over the next two days. Strong and gusty outflow winds should be expected near any storms or virga. The Flagstaff airport did have 2 periods of outflow wind gusts to 48 and 47 mph yesterday, an indication of outflow speeds possible through Monday afternoon. Satellite imagery this morning shows the monsoonal moisture plume running from NW Mexico through Tucson then northeastward through New Mexico. Satellite derived pw values are up to near 1.5 inches around Tuscon this morning. Models remain consistent in showing mid level easterly flow increasing across central and southern AZ today and this will allow moisture to slowly increase across areas along and south of I-40 through Monday. Areas along the Utah border to remain hot and nearly cloud free today as this area is under the high pressure circulation center. Starting Tuesday, models are in good agreement with moist easterly flow through Wednesday morning becoming light southerly through Wednesday. Monsoonal moisture to remain overhead through the week and daytime precip chances were nudged upward a few points along the Mogollon Rim. Max temps to cool to near normal for dates starting Wednesday. && .AVIATION...For the 18Z Package...Isolated to scattered showers and thunderstorms with possible gusts to 40kts will redevelop from KFLG- KRQE southeast this afternoon and evening until around 02z. Otherwise, expect VFR conditions. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Monsoon moisture will slowly increase northward each day. Expect deeper moisture with increasing coverage in showers and thunderstorms starting on Monday. Storm motion today and Monday will generally be from northeast to southwest. Expect erratic and gusty winds near any showers and storms. Tuesday through Thursday...An active wet Monsoon weather pattern is forecast with good shower and thunderstorm coverage each day across northern Arizona. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && $$ PUBLIC...RR/DL AVIATION...MAS FIRE WEATHER...MCS For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Tucson AZ 940 AM MST SUN JUN 26 2016 .SYNOPSIS...We now have enough moisture for isolated to scattered showers and thunderstorms this weekend. A more favorable flow regime will then provide increased coverage of showers and thunderstorms Monday through next Saturday. && .DISCUSSION...Still plenty of debris cloud this morning with embedded light showers. This is going to slow the heating a bit with initial clearing underway in portions of Cochise and Santa Cruz counties. The 12Z KTWC sounding still has plenty of moisture at 1.4 inches precipitable water. The mid level easterly flow has already increased substantially accompanied by an increase in shear that should help to organize outflow activity this afternoon. The direction favors strong outflow off the Mogollon Rim through Graham county. Latest HRRR trends push 2 strong outflows westward, including the Rim shot and a second outflow from activity in Cochise county pushing west and northwestward. The 12z UofA WRF-NAM paints a similar scenario with the outflow from the Cochise county activity pushing through the Tucson Metro area around mid to late afternoon. Minor adjustments to increase activity in the east central mountains and subsequent outflow westward, otherwise we have solid forecast trends. Please see the previous discussion below for additional details. && .AVIATION...VALID THRU 27/18Z. Isolated to scattered -TSRA/-SHRA. The best timing for TSRA at the KTUS/KOLS/KDUG terminals is mostly from 20Z this afternoon until 27/02Z this evening. Brief wind gusts to near 40 kts and MVFR conditions due to reduced visibilities will be possible with the stronger TSRA. Isolated -SHRA/-TSRA will be possible area-wide late tonight into early Monday morning. Otherwise, cloud decks generally ranging from 10k- 15k ft MSL, and surface wind terrain driven mainly less than 12 kts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect isolated to scattered showers and thunderstorms this afternoon and evening. Greater coverage of showers and thunderstorms should then occur Monday through next Saturday. Otherwise, daytime minimum relative humidity values will generally range from the mid teens to around 30 percent with fair to good nighttime recovery. 20-foot winds into Monday as well as Thursday through Saturday will be terrain driven at less than 15 mph. 20-foot winds Tuesday and Wednesday will generally be from the east at 5-15 mph with gusts of 15-20 mph. The strongest speeds Tuesday and Wednesday should prevail from shortly after sunrise into the early afternoon hours. && .PREV DISCUSSION...The hi-res models suggest a scenario late tonight similar to that presently occurring across the area. In other words, a fairly widespread convective debris cloud cover with patches of sprinkles or light rain. 26/00Z GFS/ECMWF/CMC remained fairly similar regarding the synoptic scale pattern regime over the southwestern states starting Monday and continuing into early next weekend. Strong high pressure aloft Monday is progged to become centered over southern Utah. The GFS/ ECMWF depict an inverted trough to move into southwestern AZ from the northern Gulf of California Monday. Quick glance at the U/A WRF-NAM suggests that showers/tstms Monday afternoon would only be confined to the White Mountains and near the international border adjacent Santa Cruz/southern Pima County. Thus, there is the potential that Monday may be a "down day" perhaps due to subsidence on the eastern periphery of the aforementioned inverted trough. Forecast confidence in this particular detail is somewhat low, however. Thus, for this forecast package, have continued with scattered showers/tstms mainly from Tucson eastward/southward. Thereafter, not much daily variation in shower/tstm coverage is anticipated Tuesday into next Saturday. The deterministic GFS/ECMWF/ CMC were similar with maintaining fairly ample moisture across this forecast area. These solutions were similar with the continuation of a light ely/sely mid-level flow regime thru about Wednesday. The mid- level flow regime is then progged to become more wly/swly especially from Tucson westward starting Thursday and continuing into next Saturday. This subtle change may be sufficient for at least a slight downward trend in shower/tstm coverage, especially across western sections. Again, forecast confidence is fairly low at this time in stating that a definitive downward precip trend anywhere in the area is in the offing late this week. High temps for the Tucson metro area and locales west-to-northwest of Tucson will be near normal during much of this forecast period. However, daytime temps for locales east-to-south of Tucson, such as Safford, Douglas and Nogales will average a few degs below normal this week. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Meyer/Francis Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
AREA FORECAST DISCUSSION
National Weather Service Northern Indiana
143 PM EDT SUN JUN 26 2016 .SYNOPSIS... Issued at 525 AM EDT Sun Jun 26 2016 Chances for showers and thunderstorms will increase from west to east today as an upper level system moves into the area. Isolated wind gusts greater than 50 mph and heavy rain will be the main threats with thunderstorms this afternoon and early this evening. Highs today will be near 90 with heat indices rising to near 100 degrees this afternoon. A drier and eventually cooler weather pattern will then settle in for much of next week. && .SHORT TERM...(Today and Tonight) Issued at 520 AM EDT Sun Jun 26 2016 Very warm and humid air will spread northeast into the forecast area today. Have issued a heat advisory for most of northern Indiana until 6 pm EDT given a very warm start with early morning temperatures in the 70s and given very humid air just upstream. Some clouds may hinder the warmup today, but the heat index over much of northern Indiana should rise to around 100 degrees later today. A large area of thunderstorms extended across Iowa into Wisconsin early this morning ahead of an upper trof. These storms will move east later today. Wind directions in the lower atmosphere should be relatively unidirectional and wind speed under 30 knots. Mid level lapse rates will be relatively stable, close to 6.0C/Km. CAPE values should rise to between 1500 and 2000 J/Kg per latest BUFKIT high resolution soundings. Given favorable diurnal timing, some storms will likely become strong and produce wind gusts in excess of 50 mph. Precipitable water values should climb above 2.0 inches so heavy rainfall may cause localized flooding. && .LONG TERM...(Monday through Saturday) Issued at 520 AM EDT Sun Jun 26 2016 An upper level trof is expected to amplify this upcoming week and bring dry and relatively cool weather to the area during the middle of the week. The cold front should move across the area late Monday. Lakeshore hazards along the southeast shore of Lake Michigan are likely Monday night into Tuesday as winds become northwest behind the front. Cooler weather will return during the middle of the week as the long wave trof becomes established over eastern North America. Lows should dip well into the 50s Tuesday night. Highs should be in the 70s to around 80 from Tuesday through the end of the week. && .AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon) Issued at 142 PM EDT Sun Jun 26 2016 Vfr conds xpcd through the pd. Prefntl trough in assocn/w sw trough swirling through wrn ON stretching fm wrn lwr MI swwd through wrn IL cont ewd through the aftn. Stabilization in wake of morning outflw throws some uncertainty into how things redvlp this aftn alg prefntl trough. Hwvr enough of concensus projection of fvrd placement exists to drop prior tempo tsra grouping at KSBN. While environmental flw through base of mid lvl trough remains weak...rapidly destabilizing outflw bubble w/swd extent and somewhat enhanced sfc convergence xpcd invof KFWA lt this aftn. RAP UH progs suggests a fairly stg line of convn likely to result this evening acrs ern IN/wrn OH which may yield a brief pd of +tsra w/potential mvfr conds resulting. Will cont to monitor. && .IWX Watches/Warnings/Advisories... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SYNOPSIS...Skipper SHORT TERM...Skipper LONG TERM...Skipper 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 1235 PM EDT SUN JUN 26 2016 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 400 AM EDT Sun Jun 26 2016 A frontal system will move through the area this afternoon and tonight, bringing thunderstorms to portions of the area. An isolated severe storm cannot be ruled out, but a widespread severe threat is unlikely. Heat indices in the very humid airmass will approach 100 degrees at times this afternoon. A secondary cold front will bring relief from the heat Monday night into Tuesday as high pressure builds into the area behind it. Dry conditions will dominate much of the week, with low precipitation chances returning as next weekend arrives. && .NEAR TERM /Rest of Today/... Issued at 955 AM EDT Sun Jun 26 2016 .update...Continue to slow down the arrival time storms with isolated storms by early afternoon and the best chances being 6 PM an beyond based on current trends and HRR. Tweaked Highs down a degree over the northwest half of our region due to increasing clouds. Otherwise...the rest of the near term is on track and no updates other than grids are needed at this time. Previous near term discussion follows.... Thunderstorm chances will steadily increase through the day as the cold front approaches. While ample instability will be present owing to the very warm and humid airmass ahead of the front, shear is meager at best. Suppose the significant instability could produce a pulse severe storm here or there, but do not expect anything more than that. Hydrologic issues may be the more pressing concern as precipitation efficiency should be quite high with deep warm cloud owing to a freezing level pushing 14kft, pseudotropical with very deep saturation, and storm motions which are likely to be somewhat slow contributing to the potential for some heavy rainfall. Additionally, observed rainfall in the last week or two has been roughly 150 to as much as 400 percent of normal in some portions of central Indiana. Will hit the flood threat in the HWO. Consensus temperatures looked reasonable with minor upward tweaks where storms are expected to arrive latest in the day, mainly south and southeast. Maximum heat index values will likely approach and may briefly exceed 100 degrees across portions of the area this afternoon. Indices should remain below advisory criteria but will be mentioned in the HWO as this will be one of the hotter days of the year thus far. && .SHORT TERM /Tonight through Tuesday Night/... Issued at 400 AM EDT Sun Jun 26 2016 Storm threat will persist into the evening across much of the area and the overnight for at least portions of central Indiana. Again, while an isolated pulse severe storm cannot be ruled out, think sporadic hydrologic issues will be the more likely threat to require monitoring. As the front exits the area late tonight into early Monday morning, will rapidly taper off precip chances with only the far southern area carrying a slight chance into the first few hours of the day on Monday. The remainder of the short term looks dry, although will have to monitor secondary cold frontal passage Monday night into Tuesday as dewpoints will still be in the 60s ahead of it. Consensus temperatures appeared632 reasonable with minor tweaks throughout the period, mainly late in the period. && .LONG TERM /Wednesday through Saturday/... Issued at 241 AM EDT Sun Jun 26 2016 Models and ensembles in good agreement that Canadian high pressure will allow for dry weather with slightly below normal temperatures through Thursday. Then, an upper trough will pivot east across the Great Lakes and push a back door cold front across central Indiana early next weekend. Regional blend suggests there could be a few showers and thunderstorms around over all or parts of the area starting Thursday night and continuing through Saturday, when the front will likely move through. Temperatures should bounce back to near normal with highs in the lower to mid 80s by Thursday or Friday. Look for lows in the 50s Wednesday night and the 60s the rest of the long term. && .AVIATION /Discussion for 261800Z TAF Issuance/... Issued at 1235 PM EDT Sun Jun 26 2016 VFR conditions expected throughout the period with the exception of restrictions within convection later this afternoon and evening. Skies remain mostly sunny early this afternoon with light southwest winds doing little to deter the muggy airmass over the region. Cold front remains northwest of central Indiana currently with a remnant outflow boundary from overnight storms in the upper Midwest noted on satellite and radar over the northern Wabash Valley. This feature may serve as the initial catalyst to fire convection as it drops further into the forecast area over the next few hours. With little shear and forcing aloft present however...expect storms remain isolated to widely scattered through about 21Z. A continued VCTS mention will suffice at all sites. Will highlight SW winds veering to westerly by early evening...but likely to see variable wind direction for a period of time once the outflow passes. Hi-res guidance continues to develop a broken line of convection with the front for late afternoon and evening. Confidence is higher in greater threat for convective impacts at all terminals during this period and despite some question as to how extensive storm coverage will eventually become in the absence of greater shear...feel a 4 hour tempo group for storms producing brief restrictions is prudent at all sites. Any lingering convection will move south of the terminals with the front overnight. A brief period of mid to high level clouds will give way to mainly clear skies on Monday as deep subsidence spreads into the region on N/NW winds. && .IND Watches/Warnings/Advisories...NONE. && $$ SYNOPSIS...NIELD NEAR TERM...NIELD/MK/JH SHORT TERM...NIELD LONG TERM...MK AVIATION...RYAN
Area Forecast Discussion National Weather Service Indianapolis IN 1012 AM EDT SUN JUN 26 2016 .UPDATE... The AVIATION section has been updated below. && .SYNOPSIS... Issued at 400 AM EDT Sun Jun 26 2016 A frontal system will move through the area this afternoon and tonight, bringing thunderstorms to portions of the area. An isolated severe storm cannot be ruled out, but a widespread severe threat is unlikely. Heat indices in the very humid airmass will approach 100 degrees at times this afternoon. A secondary cold front will bring relief from the heat Monday night into Tuesday as high pressure builds into the area behind it. Dry conditions will dominate much of the week, with low precipitation chances returning as next weekend arrives. && .NEAR TERM /Rest of Today/... Issued at 955 AM EDT Sun Jun 26 2016 .update...Continue to slow down the arrival time storms with isolated storms by early afternoon and the best chances being 6 PM an beyond based on current trends and HRR. Tweaked Highs down a degree over the northwest half of our region due to increasing clouds. Otherwise...the rest of the near term is on track and no updates other than grids are needed at this time. Previous near term discussion follows.... Thunderstorm chances will steadily increase through the day as the cold front approaches. While ample instability will be present owing to the very warm and humid airmass ahead of the front, shear is meager at best. Suppose the significant instability could produce a pulse severe storm here or there, but do not expect anything more than that. Hydrologic issues may be the more pressing concern as precipitation efficiency should be quite high with deep warm cloud owing to a freezing level pushing 14kft, pseudotropical with very deep saturation, and storm motions which are likely to be somewhat slow contributing to the potential for some heavy rainfall. Additionally, observed rainfall in the last week or two has been roughly 150 to as much as 400 percent of normal in some portions of central Indiana. Will hit the flood threat in the HWO. Consensus temperatures looked reasonable with minor upward tweaks where storms are expected to arrive latest in the day, mainly south and southeast. Maximum heat index values will likely approach and may briefly exceed 100 degrees across portions of the area this afternoon. Indices should remain below advisory criteria but will be mentioned in the HWO as this will be one of the hotter days of the year thus far. && .SHORT TERM /Tonight through Tuesday Night/... Issued at 400 AM EDT Sun Jun 26 2016 Storm threat will persist into the evening across much of the area and the overnight for at least portions of central Indiana. Again, while an isolated pulse severe storm cannot be ruled out, think sporadic hydrologic issues will be the more likely threat to require monitoring. As the front exits the area late tonight into early Monday morning, will rapidly taper off precip chances with only the far southern area carrying a slight chance into the first few hours of the day on Monday. The remainder of the short term looks dry, although will have to monitor secondary cold frontal passage Monday night into Tuesday as dewpoints will still be in the 60s ahead of it. Consensus temperatures appeared632 reasonable with minor tweaks throughout the period, mainly late in the period. && .LONG TERM /Wednesday through Saturday/... Issued at 241 AM EDT Sun Jun 26 2016 Models and ensembles in good agreement that Canadian high pressure will allow for dry weather with slightly below normal temperatures through Thursday. Then, an upper trough will pivot east across the Great Lakes and push a back door cold front across central Indiana early next weekend. Regional blend suggests there could be a few showers and thunderstorms around over all or parts of the area starting Thursday night and continuing through Saturday, when the front will likely move through. Temperatures should bounce back to near normal with highs in the lower to mid 80s by Thursday or Friday. Look for lows in the 50s Wednesday night and the 60s the rest of the long term. && .AVIATION /Discussion for the 261500Z TAF Update/... Issued at 1012 AM EDT Sun Jun 26 2016 TAFs are in decent shape for the mid morning update and only making subtle adjustments. Main change is to slow initial VCTS mention by an hour or two this afternoon. Already seeing a few showers develop in the warm humid airmass...but current hi-res guidance favors isolated convection developing primarily after 17-18Z with more substantial convection associated with the cold front set to impact the terminals late afternoon and evening. 12Z discussion follows. Good confidence in VFR conditions through much of the period except MVFR and possibly IFR at times in thunderstorms. The first batch of convection should move into the LAF and HUF areas after 14z and IND and BMG after 15z as a warm front moves across the area. Then, a more solid line will be dropping southeast over the terminals 21z and later this afternoon near and just ahead of an approaching cold front per the HRRR. The HRRR is currently handling the convection rather well. Things will be winding down tonight after the cold front moves through. Winds will be south and southwest today and increase to around 10 knots 14z-16z. Winds near term will then become west and northwest 7 knots or less post frontal tonight. && .IND Watches/Warnings/Advisories...NONE. && $$ SYNOPSIS...NIELD NEAR TERM...NIELD/MK/JH SHORT TERM...NIELD LONG TERM...MK AVIATION...MK/RYAN