Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/09/16

Area Forecast Discussion...UPDATED
National Weather Service Little Rock AR
620 PM CDT FRI JUL 8 2016

.DISCUSSION...

Updated to include the 00Z aviation discussion below...

&&

.AVIATION...

Some SHRA/TSRA will continue to be possible during the overnight
period...though exact location will be somewhat uncertain. As a
result...will just mention some VCTS/VCSH. Chances for precip
will remain possible for Sat...with a similar scenario expected
regarding coverage and location. Some patchy fog will also be
possible...especially across the NRN sites where some precip has
been seen recently.

&&

.PREV DISCUSSION...(ISSUED 305 PM CDT FRI JUL 8 2016)

SHORT TERM...Tonight through Saturday Night

Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR
this aftn...assocd with MCV that worked into NW AR earlier in the
day. Severe t-storm watch in effect for those areas until 9 pm tngt.
Have adjusted POPS accordingly to reflect current trends...with
dcrsg coverage expected later this evening as the upr energy shifts
away fm the FA.

Upr rdg is fcst to contract ovr the FA heading into weekend...
allowing a series of upr impulses to move SEWD acrs AR. This wl
result in several more convective complexes to form upstream and
eventually affect the region. Timing and coverage of each sys wl be
the main fcst concern. Still expect to see the best chcs acrs the
NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch
or two can be expected ovr NRN AR...with lesser chcs the further S
you go. Rain and clouds wl hold down high temps ovr NRN and parts of
CNTRL AR...with the warmest readings in the SRN part of the CWA.

Long Term...Sunday Through Friday

The extended forecast will start with rain in the forecast with the
nearly stalled frontal boundary over AR. The best chances will be
over central and northern AR on Sunday, then as the boundary is
expected to lift northward on Monday, a lower chance and more in the
east to northeast will be seen. On Tuesday and much of the rest of
the week, a more isolated afternoon to evening chance of convection
will be seen during the heat of the day...as the upper high pressure
ridge builds more into the Plains and caps some of the potential.
The overall chance of strong to severe storms will be low and
isolated. Otherwise...Temperatures will generally run above normal
values...as humidity levels remain high. Heat index values will also
remain in the 90s to 100 degrees to around 105 most days.

&&

.LZK Watches/Warnings/Advisories...NONE.
&&

$$


Aviation...62



Area Forecast Discussion National Weather Service Little Rock AR 305 PM CDT FRI JUL 8 2016 .SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. && .Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...44 / Long Term...59
Area Forecast Discussion National Weather Service Little Rock AR 112 PM CDT FRI JUL 8 2016 .AVIATION...08/18Z Taf Cycle Remnants from morning MCS now affecting parts of NWRN AR. Expect additional sctd SHRA/TSRA to form this aftn acrs NRN and WRN AR along assocd outflow bndry/s. Have TEMPO groups at KHRO and KBPK this aftn to account for this. Outside of convection...VFR conds wl prevail thru the pd. Cannot rule out some SCTD low clouds again Sat mrng...but moisture lvls not as abundant to mention any CIGS attm. /44/ && .PREV DISCUSSION...(ISSUED 1139 AM CDT FRI JUL 8 2016) UPDATE... Cont to monitor convective trends to our NW this mrng. MCS conts to work EWD this aftn and affect mainly the NRN third of the FA. While an overall weakening trend has been noted...expect storms to refire as we apch max aftn heating. Some sctd SHRA/TSRA has formed in the last hour over parts of W-CNTRL AR in the vcnty of the an assocd outflow bndry and along the SERN periphery of the higher lvl cloud shield. Just made some minor adjustments to POPS this aftn to account for radar/Hi-Res model trends. As expected...high temps ovr N AR wl be held down some by abundant clouds/rain chcs. Cannot rule out a few strong/svr storms this aftn as well...with gusty winds being the main concern. Rest of fcst in good shape. All updates are out. /44/ PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1139 AM CDT FRI JUL 8 2016 .UPDATE... Cont to monitor convective trends to our NW this mrng. MCS conts to work EWD this aftn and affect mainly the NRN third of the FA. While an overall weakening trend has been noted...expect storms to refire as we apch max aftn heating. Some sctd SHRA/TSRA has formed in the last hour over parts of W-CNTRL AR in the vcnty of the an assocd outflow bndry and along the SERN periphery of the higher lvl cloud shield. Just made some minor adjustments to POPS this aftn to account for radar/Hi-Res model trends. As expected...high temps ovr N AR wl be held down some by abundant clouds/rain chcs. Cannot rule out a few strong/svr storms this aftn as well...with gusty winds being the main concern. Rest of fcst in good shape. All updates are out. /44/ && .PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 620 AM CDT FRI JUL 8 2016 .UPDATE... Updated to include 12z aviation discussion. && .AVIATION... Some patchy MVFR 1500-2000ft ceilings possible around central and southern AR terminals the next few hours, then mainly VFR conditions expected. Winds out of the SW today 7-12kts gusting as high as 20kts at times. Could see isolated/scattered SH/TS activity across mainly northern areas this afternoon/evening and then again after midnight. Widespread mid/high clouds will be in place for much of the TAF period as well. && .PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016 ) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion National Weather Service Little Rock AR 354 AM CDT FRI JUL 8 2016 .SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. && .LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 93 74 87 72 / 40 30 50 60 Camden AR 97 77 96 75 / 10 20 30 30 Harrison AR 89 71 84 69 / 50 50 50 50 Hot Springs AR 95 77 92 75 / 20 30 40 30 Little Rock AR 96 78 93 76 / 20 30 40 40 Monticello AR 96 79 95 76 / 10 20 30 30 Mount Ida AR 94 75 92 73 / 20 30 40 30 Mountain Home AR 90 72 85 70 / 50 50 50 60 Newport AR 94 75 88 73 / 40 30 50 50 Pine Bluff AR 95 78 92 75 / 20 20 40 30 Russellville AR 94 76 90 74 / 20 40 50 40 Searcy AR 95 76 91 73 / 20 30 50 50 Stuttgart AR 95 77 92 75 / 20 20 40 40 && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...226 / Long Term...46
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1225 AM CDT FRI JUL 8 2016 .UPDATE... Updated to include 06z aviation discussion. && .AVIATION... Showers and thunderstorms slowly moving SE out of SW MO and SE KS this morning may bring vicinity SH/TS activity to northern AR terminals this morning as they dissipate. Otherwise, MVFR ceilings expected across central/southern AR around daybreak once again with primarily VFR conditions seen otherwise. Winds will be out of the SW again with speeds of 8-12kts and gusts to 20kts at times. && .PREV DISCUSSION...(ISSUED 711 PM CDT THU JUL 7 2016 ) AVIATION...08/00z Taf Cycle Look for VFR conds to cont thru much of pd. Sct-bkn low clouds wl again dvlp toward sunrise Fri...mainly acrs CNTRL and SRN AR... resulting in ocnl MVFR cigs. Hi-Res model data conts to suggest a complex of storms forming forming later tngt acrs SRN KS... eventually working SEWD into parts of NW AR Fri mrng. Included PROB30 groups at KHRO and KBPK to account for any storms that may form along residual small scale bndry`s later in the day. /44/ PREV DISCUSSION...(ISSUED 252 PM CDT THU JUL 7 2016) DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion National Weather Service Little Rock AR 711 PM CDT THU JUL 7 2016 .AVIATION...08/00z Taf Cycle Look for VFR conds to cont thru much of pd. Sct-bkn low clouds wl again dvlp toward sunrise Fri...mainly acrs CNTRL and SRN AR... resulting in ocnl MVFR cigs. Hi-Res model data conts to suggest a complex of storms forming forming later tngt acrs SRN KS... eventually working SEWD into parts of NW AR Fri mrng. Included PROB30 groups at KHRO and KBPK to account for any storms that may form along residual small scale bndry`s later in the day. /44/ && .PREV DISCUSSION...(ISSUED 252 PM CDT THU JUL 7 2016) DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .LZK Watches/Warnings/Advisories... Heat Advisory until 8 PM CDT this evening FOR Arkansas-Bradley- Calhoun-Clark-Cleburne-Cleveland-Conway-Dallas-Desha-Drew- Faulkner-Garland-Grant-Hot Spring-Independence-Jackson-Jefferson- Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery-Ouachita-Perry- Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White- Woodruff-Yell. && $$
Area Forecast Discussion National Weather Service Little Rock AR 252 PM CDT THU JUL 7 2016 .DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. && .SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. && .LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 95 78 94 75 / 40 30 40 30 Camden AR 97 77 96 78 / 20 20 10 20 Harrison AR 93 76 90 72 / 50 20 50 50 Hot Springs AR 96 79 95 77 / 20 20 20 30 Little Rock AR 96 78 96 78 / 20 20 20 30 Monticello AR 96 78 96 79 / 20 20 10 20 Mount Ida AR 95 78 93 75 / 20 20 20 30 Mountain Home AR 95 76 91 73 / 60 30 50 50 Newport AR 95 78 95 76 / 40 30 40 30 Pine Bluff AR 96 77 94 78 / 20 20 20 20 Russellville AR 98 77 94 76 / 30 20 20 40 Searcy AR 96 77 95 76 / 30 20 20 30 Stuttgart AR 96 77 95 78 / 20 20 20 20 && .LZK Watches/Warnings/Advisories... Heat Advisory until 8 PM CDT this evening FOR Arkansas-Bradley- Calhoun-Clark-Cleburne-Cleveland-Conway-Dallas-Desha-Drew- Faulkner-Garland-Grant-Hot Spring-Independence-Jackson-Jefferson- Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery-Ouachita-Perry- Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White- Woodruff-Yell. && $$ Short Term...59 / Long Term...66
Area Forecast Discussion...Updated for Aviation National Weather Service Little Rock AR 1215 PM CDT THU JUL 7 2016 .AVIATION... Overall VFR flight conditions are expected. Patchy MVFR may be seen especially associated with showers or isolated thunderstorms. Winds are expected to be southeast to southwest at 10 to 20 mph with some gusts to around 25 mph in spots. After sunset, winds will lower to 5 to 15 mph. Tonight, isolated convection may be seen over northern Arkansas and affect KHRO and KBPK Tafs. Winds will lower to mainly below 10 mph. (59) && .Prev Discussion.../ Issued 1000 AM CDT THU JUL 7 2016 Earlier update to add scattered convection over northern AR. Complex over MO has helped develop this convection associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR. Will monitor for possible lake wind advisory. Otherwise, temperatures will warm to the 90s today, and with the added humidity, heat index values will reach around 105 degrees. A heat advisory is in effect for most of AR except the northern areas. Late morning update will fine tune convection chances, possibly adding a bit more southern areas in slight chance area. (59) && .PREV DISCUSSION...(ISSUED 358 AM CDT THU JUL 7 2016 SHORT TERM...Today Through Friday Night Similar setup to yesterday across the region with surface high pressure in place to the southeast and low pressure noted across the Southern Plains. Two MCS`s noted across the region with the first impacting Tennessee/Kentucky and the second moving out of SE Nebraska into northeastern Kansas. Should see fewer impacts to the forecast area from upstream MCS in Kansas due to more northerly location and easterly trajectory. Early morning HRRR runs attempt to initiate some shower and thunderstorm activity across E Oklahoma with a weak shortwave in the mean flow and shift this activity toward Arkansas throughout the day. No activity has manifested itself as of 09z so will keep forecast dry attm though wouldn`t be surprised to see at least a few isolated showers develop. SW flow at the surface will be in place again today and winds will be enhanced due to increased pressure gradient. Wind speeds will likely be aoa 12-18mph with gusts as high as 25mph at times. The other notable mention of the day goes to heat index values across the state. With dewpoints in the 70s and temps cranking into the mid to upper 90s, another run at heat index values of 105 will be made this afternoon. Rain chances will be in place across mainly northern Arkansas on Friday as a surface boundary approaches from the NW. Additionally, the H500 pattern begins to show signs of transitioning to more of an active period with more of a NW flow expected. Will have to keep an eye on temps/heat indices Friday as heat indices could approach heat advisory levels once again across the southern half of the state. Could see chances for a more notable thunderstorm complex approaching the state from the northwest late Friday night. LONG TERM...Saturday Through Wednesday As a ridge of high pressure weakens over the southeast United States, a cold front will be allowed to drop through the Ohio and Tennessee Valleys during the upcoming weekend. The front may actually make it into northeast Arkansas. Isolated to scattered showers and thunderstorms are in the forecast. Given more clouds, it will be slightly cooler. A few storms may be severe as the front nears the region. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected at this point. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will be noted out west. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. Readings may be a touch below average toward the Missouri border this weekend near the aforementioned front. && .LZK Watches/Warnings/Advisories... Heat Advisory from 10 AM this morning to 8 PM CDT this evening FOR Arkansas-Bradley-Calhoun-Clark-Cleburne-Cleveland-Conway- Dallas-Desha-Drew-Faulkner-Garland-Grant-Hot Spring-Independence- Jackson-Jefferson-Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery- Ouachita-Perry-Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White-Woodruff-Yell. && $$ Aviation...226
AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
905 PM PDT FRI JUL 8 2016 .SYNOPSIS... Onshore flow will continue night through morning low clouds and fog for the coast and valleys into next week that should clear to the beaches by the afternoons. Breezy winds may occur in the mountains and deserts into Monday. Near normal temperatures will persist through Monday. A high pressure system should build in from Tuesday to Thursday for a slow warming trend. && .UPDATE... Southwest flow aloft remains in place between a trough of low pressure off the British Columbia Coast and a ridge of high pressure over the Gila River Basin. Closer to the surface, onshore flow remains across the area keeping persistent night through morning stratus in place over the coasts and valleys. As high pressure wobbles west through Saturday, onshore flow will weaken some and the marine depth will thin slightly. Onshore gradients are about a half millibars weaker this evening than last evening with the marine layer depth about 200 feet thinner. The latest KLAX amdar soundings indicate the marine layer depth near 950 feet this evening, which will likely deepen to near 1800 feet by Saturday morning if NAM BUFR time height sections play out. A little less stratus coverage should be expected tonight with a slight warm-up taking place over today. 500 mb heights rise and 1000-500 mb thickness values climb again for Saturday. Stratus may be difficult to clear out from the beaches on Saturday afternoon. A few tweaks have been made to temperatures on Saturday, warming the areas outside of the marine influence and keeping the immediate coastal locations near persistence. A northerly pressure gradient will start to develop and tighten on Saturday night and continue through weekend. Gusty Sundowner winds will likely develop each night from Saturday night and into Tuesday morning. Latest NAM-WRF solutions tighten KSBA-KSMX on Saturday evening to near -4 mb on Saturday evening and slightly above -4 mb on Sunday evening. A wind advisory may need to be considered by future shifts once confidence in timing and strength becomes a bit more apparent. && .PREV DISCUSSION... SHORT TERM...A low pressure system currently just west of Vancouver will drop into Oregon tomorrow with a dry trough extending into central California...then move eastward through Monday. Northwest winds will strengthen Saturday night through Sunday night as a result. Southern Santa Barbara County will likely need a wind advisory Saturday night through Sunday night...while the LA Mountains and the Antelope Valley should need one for late Sunday afternoon and night. Gusts into the 50 mph range are likely in these areas during the wind peak Sunday night. Monday will also see some breezy northwest winds...but should be the weakest of the next three days. Stratus coverage and temperatures on Saturday should be similar to today...save for less stratus over SBA and SLO counties thanks to the dry front passage and the SMX-BFL pressure gradient significantly weakening by 3 mb. The Northwest flow will likely keep most of Ventura and southern SBA counties stratus clear Sunday and Monday...while a strong coastal eddy will push clouds to the coastal slopes in LA County with some spits of drizzle possible. The Central Coast stratus remains a tough call on Sunday...but should be mostly cloud-free on Monday as breezy northeast flow forms in the morning. All of this adds up to a mixed bag of temperature trends with the winds and stratus evolution being the main drivers. LONG TERM...An upper level ridge of high pressure currently over north-central Mexico will expand into California Tuesday through Thursday. This will bring a gradual warming trend to the region...with interior valleys approaching 100 degrees by Wednesday or Thursday. LA and Ventura County coastal and valley areas should also see warming with the air mass change and likely shrinking of the marine layer. SBA and SLO counties on the other hand will see a ceasing of the northwest flow and a return to onshore flow...which should increase stratus coverage and largely neutralize the warming trend. Both the GFS and ECMWF are advertising a weak trough dropping down into California by as early as Friday...which would enhance the marine layer and usher in some modest cooling. The GFS ensemble members are in very good agreement with this timing especially considering how far out this is...so did start the cooling trend in the forecast. && .AVIATION...09/0000Z. At 00Z, the marine layer depth was around 950 feet deep at KLAX. The top of the inversion was around 3100 feet with a temperature near 23 degrees Celsius. North of Point Conception...Predominantly LIFR to IFR conditions will spread into Central Coast Terminals through 06Z then likely deteriorate to LIFR between 08Z and 15Z. There is a 30 percent chance of LIFR conditions at KPRB between 13Z and 16Z. South of Point Conception...IFR to MVFR conditions will spread into coastal and valley terminals through 13Z. Highest confidence in IFR conditions exists north of KNTD. Coastal terminals may struggle to clear on Saturday afternoon. KLAX...MVFR conditions will spread in through 05Z at the latest and linger through at least 17Z. There is a 50 percent chance of MVFR conditions developing between 01Z and 05Z. KBUR...There is a 70 percent chance of MVFR conditions spreading in between 10Z and 13Z and lingering until 16Z. && .MARINE...08/800 PM. Will continue with the gale watch for increasing northwest winds. Northwest winds will likely increase Saturday afternoon and peak Sunday in strength over the waters from Piedras Blancas to San Nicolas Island and out 60 nm. Northwest winds will diminish Monday but there is a chance SCA for hazardous sea conditions as well as northwest gusts to 25 knots through Wednesday. Extra currents and surging along exposed south facing shores will result from swells originating from tropical cyclones Blas and Celia...and from the Southern Ocean through the period. Swell from Blas will linger through Saturday. Swells generated by Celia are expected to begin to arrive next week Wednesday. && .FIRE WEATHER...08/300 PM. Elevated fire danger will continue across interior sections through the weekend. For this afternoon, the gusty onshore winds will mostly be focused across the Antelope Valley and Los Angeles County mountains. Over the weekend, west to north winds are expected to become more widespread across interior sections, including gusty sundowner winds across the western portions of the Santa Barbara south coast and Santa Ynez mountains. Saturday afternoon through Saturday night, wind gusts between 35 and 45 mph will be common across the mountains, Antelope Valley, and western portions of the SBA South Coast, then potentially ramping up to between 40 and 50 mph on Sunday afternoon and night. On Saturday, humidities will generally remain above 20 percent with the exception of the Antelope Valley where values in the teens can be expected. By Sunday afternoon and evening, more widespread humidities falling into the teens (and possibly single digits across higher mountains) can be expected across interior sections bringing the potential for critical fire weather conditions. The greatest threat of critical conditions exceeding 6 hours will be the mountains and Antelope Valley on Sunday afternoon and evening, where a fire weather watch has been posted. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...Fire Weather Watch in effect from Sunday afternoon through late Sunday night For zones 252>254. (See LAXRFWLOX). Fire Weather Watch in effect from Sunday morning through Sunday evening For zone 259. (See LAXRFWLOX). PZ...Gale Watch in effect from Saturday afternoon through late Sunday night For zones 645-670-673-676. (See LAXMWWLOX). Small Craft Advisory in effect until 3 PM PDT Saturday For zones 670-673-676. (See LAXMWWLOX). && $$ PUBLIC...Hall/Kittell FIRE...Gomberg AVIATION...Hall MARINE...Smith SYNOPSIS...Seto/Hall weather.gov/losangeles
  [top] Area Forecast Discussion National Weather Service Phoenix AZ 900 PM MST FRI JUL 8 2016 .SYNOPSIS... A dry and stable airmass will remain across much of the desert southwest through next week, giving the region a significant break in the monsoon, with little or no chance for rainfall. Afternoon temperatures on the lower deserts will remain near, or a few degrees above, normal through the period. && .DISCUSSION... Early this evening, deep southwest flow aloft was present over all but far southeast Arizona, as deep upper troffing pushed into the Pacific Northwest coast, shunting the main high center southeast of Arizona and setting up stronger west to southwest flow aloft into the desert southwest. This deep southwest flow was easily seen in the area raobs, most prominent in Flagstaff and to slightly lesser an extent in Phoenix. The west flow has continued to erode moisture over the central deserts, the PWAT in Phoenix this evening was down to just 0.73 inches and surface dewpoints over the central deserts at 8 pm were mostly in the middle 40s - mostly down 3-10 degrees from 24 hours ago. IR imagery at 8 pm showed clear skies area wide. One small disturbance rotating around the upper high to our southeast had pushed up into far southeast Arizona this evening, increasing PWAT at Tucson to almost 1.3 inches and could be seen in the TUS sounding as a layer of southeast winds near 500 mb. The overall deep west/southwest flow impinging on the rest of Arizona ahead of the Pacific northwest troffing will keep this feature well to our southeast and it should not affect our weather tonight. For the rest of the night we can expect generally clear skies and gradually decreasing west winds along with mild to warm overnight low temperatures. Forecasts look to be in good shape and no updates are planned. .PREVIOUS DISCUSSION... Tonight through Saturday... Increasing westerly flow ahead of a deep upper trof is expected to continue to scour out any remaining monsoon moisture over extreme SE and eastern AZ during this period. The latest HRRR model run keeps all convective activity confined to areas to the south and east of Tucson and over the white Mountains, well outside of our CWA this afternoon/evening, with even less activity on tap on Saturday. 500 mb heights in the 593-595 dm range, 500 mb temps in the -4C to -5C range, along with mostly clear skies will allow temperatures to rise a bit above normal again on Saturday, with lower desert highs mostly in the 108-112 degree range. Sunday through next Friday... Further drying is expected across the region during this period as a very deep, and cold upper low center (for July) moves across the Northern Rockies during the early part of next week, bringing a chance for some rare mid-summer snowfall to the higher elevations of MT/WY. To the south of this low center, a band of anomalously strong westerlies are expected to move across the Great Basin/northern AZ region Sun-Tue. 700mb winds are expected to reach 30 kts, or even greater across parts of northern AZ, which are in the 99% (or higher) climatological percentile for this time of year, according to the NAEFS percentile tables. The main impact from this belt of very strong winds will be to mix drier air down to the sfc across the region, with sfc dewpoints likely falling into the 30s, or even 20s across most of our CWA. The dry airmass, combined with a bit of cooling aloft, will likely allow many outlying lower desert locations to see lows in the 70s each night. These cooler temperatures, combined with the lower RH`s will result in the nights feeling noticeably more pleasant than what we typically see this time of year. Highs will be near or just a bit above normal, mostly in the 105-110 degree range across the lower deserts. PWATS across the region will also be well below normal, in the 0.50-0.75 inch range, which is 1-2 SD below normal. Needless to say, chances for rainfall/thunderstorms during this entire period will be basically at zero as our extended break in the monsoon continues. && .AVIATION... South-Central Arizona including KPHX, KIWA and KSDL: Not much change in the overall weather pattern expected over the next 24 hours...and likely for the next several days or more as dry southwest to west flow aloft will dominate the weather affecting the Phoenix area terminals. Skies to be genly clear next 24 hours at all sites; there is no threat of weather of any kind through the weekend including storms or gusty outflow winds. Otherwise winds will hold onto typical diurnal tendencies, although they may be a bit slow to turn back to the east/southeast after midnight. Again, we may see some afternoon and early evening gustiness out of the west on Saturday but really there are no aviation concerns for the near future. Southeast California/Southwest Arizona including KIPL and KBLH: Dry weather expected across the lower deserts next 24 hours with skies to be clear. Winds should favor the south to southwest at KBLH next 24 hours with some afternoon gustiness possible on Saturday. Evening west winds at KIPL likely will return to the southeast during the morning hours on Saturday, then returning again to the west during the early evening hours Saturday with a few gusts to 20kt possible. No aviation concerns at the TAF sites for at least the next 24 hours. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Monday through Friday... An extended break in the Monsoon activity will continue into work week, with unseasonably strong westerly flow aloft and dewpoints generally below the typical Monsoonal values of 50 to 60 degrees. Conditions look to be at their driest Monday as a strong trough passes through the Great Basin to our north and spreads a drier airmass into the Southwest region. With temperatures hovering near a warm seasonal average, minimum afternoon humidity levels will fall to around 10% over lower elevations, and 15-20% in higher terrain. Overnight recovery will only be fair. Occasionally breezy southwest afternoon winds will affect the region, however speeds will remain well below any critical thresholds. Overall, weather conditions will mirror a typical early/mid June versus mid July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...CB PREVIOUS DISCUSSION...Percha AVIATION...CB FIRE WEATHER...Nolte/Kuhlman
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
636 PM CDT FRI JUL 8 2016 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Saturday) Issued at 256 PM CDT FRI JUL 8 2016 Despite some morning clouds and an easterly wind across the area, temperatures have risen into the upper 80s to near 90, save the far south which is still holding in the lower 80s as clouds continue there. Several small waves noted in the flow, one of which is approaching central kansas at this hour. Experimental HRRR has a relatively reasonable solution that brings the MCV into the CWA and interacts with an outflow moving up from the south out of earlier convection, and brings a round of showers and thunderstorms across western and southern areas later this afternoon into the evening. Wind fields are weak, although CAPE could be enough to generate some wind with storms that develop. LLJ is only around 25kts overnight, but may redevelop storms over central/south central Kansas overnight and move eastward across mainly our southern counties. Only carrying slight chance to low chance PoPs given coverage and uncertainty. Lows tonight forecast near 70 with highs on Saturday in the upper 80s to low 90s. .LONG TERM...(Saturday Night through Friday) Issued at 256 PM CDT FRI JUL 8 2016 No major changes made in the extended with still some variances in model guidance on timing and coverage of precipitation. Best chances for seeing more widespread showers and thunderstorms will be with the arrival of a cold front on Tuesday. More details below. Temporary ridging aloft Saturday night and Sunday should keep much of the area dry. Strong upper trough across the Inter Mountain West deepens a lee trough over the Rockies Sunday and Monday, increasing southerly winds at 10 to 15 mph sustained in the afternoon. Gusts up to 30 mph are possible, alleviating slightly the hot and humid conditions with readings in the lower and middle 90s. The aforementioned upper trough ejects over the northern plains Monday evening and Tuesday, surging the cold front into north central KS in the overnight hours. Guidance continues to exhibit high confidence in this scenario and have raised pops into the likely category near the KS and NE border. Ample mixed layer CAPE and effective shear parameters near 40 kts could develop a few strong to severe storms over north central areas. This activity pushes south and east on Tuesday, spreading chances towards the entire CWA. Models differ some Tuesday evening onward as the frontal boundary hangs up across the area. Subtle impulses embedded within the northwesterly flow aloft signals multiple rounds of thunderstorms, especially on Wednesday evening. Temps hover near normal values in the lower 90s for highs and low 70s for overnight lows, likely to drop into the 80s by the end of the period as the frontal boundary shifts south of the area. && .AVIATION...(For the 00Z TAFS through 00Z Saturday Evening) Issued at 636 PM CDT FRI JUL 8 2016 VFR conditions are expected outside of any convection. Confidence is not high as models offer differing solutions on convective development through 05Z. Therefore will not mention now and will monitor for tsra inclusion in terminals. Winds light from the east to southeast generally under 10 kts. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...67 LONG TERM...Prieto AVIATION...53
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
315 PM CDT THU JUL 7 2016 .SHORT TERM...(This Evening through Friday) Issued at 311 PM CDT THU JUL 7 2016 Early morning convection brought a swath of rainfall northwest through southeast across the forecast area, and left an outflow over eastern Kansas throughout the morning hours. Temperatures now mixing out and rising into the upper 80s and low 90s. Dewpoints also slow to rise, with Concordia at this hour still at 66F while southern areas increasing into the low 70s. End result will be a few hours in our southern and eastern areas with heat indicies in the 100 to 103 range, just shy of criteria for an advisory. Satellite imagery and wind fields show boundary over north central Kansas near the NE border, but lift remains generally weak in this area to tap into the instability aloft. Storms developing along the front up into Nebraska and extending into Minnesota, with this cluster expected to build east and southward with time. Much of our area has a strong cap in place with 16-18C at 700mb, and with lack of a strong source of forcing, think areas that have the best chance for strong storms are far eastern counties on the edge of the cap and where 850mb winds veer to the SW into the evening hours. Enough cape, wind and steep lapse rates aloft to make wind the primary concern with small hail also a possibility. Think that the boundary farther to the west will have a hard time generating precipitation, and have lower chances as you go westward into north central Kansas. On Friday...Front is forecast to have moved south and west of the area. Convection is forecast to develop in western Kansas along the front as a shortwave moves into the state. At this time think impacts of rain chances will be primarily in our west and south, given location of the front and some likely reinforcement of its position from the cold pool from overnight convection. .LONG TERM...(Friday Night through Thursday) Issued at 311 PM CDT THU JUL 7 2016 Friday Evening through Sunday...Underneath westerly flow aloft, an embedded impulse is progged to lift north and east from the southwest CONUS into the central Plains Friday evening into Saturday. Convergence along the h85 boundary Friday evening in conjunction with a stout llj up to 30 kts will develop another round of thunderstorms across portions of central KS. As a shortwave trough continues eastward during the day Saturday, thunderstorms remain possible especially along and south of the Interstate 70 corridor where the boundary remains stationary. With the potential for cloud cover and precipitation, highs are generally in the mid to upper 80s. Further west, where better mixing and lesser cloud cover resides, highs in the lower 90s are expected. This trend continues into early evening as activity gradually shifts southeast, creating a quiet evening for the area with mostly cloudy skies and lows near 70. A warmer and drier forecast is in store on Sunday as upper ridging builds overhead while the frontal boundary edges towards Missouri. Highs are progged in the lower 90s for Sunday. Sunday night through Wednesday...An amplified trough is expected to be located across the Western United States at the beginning of the period. Weak lead waves ejecting from the base of the trough could lead to thunderstorm development Sunday night and Monday. A more substantial wave is depicted by both the EC and GFS on Tuesday, however the bulk of forcing looks to go north of the outlook area. Have Chance PoPs Tuesday afternoon and evening as a weak surface boundary will setup in the area. This boundary in conjunction with weak upper level forcing could provide enough convergence for thunderstorm development. With a strong cap in place, widespread thunderstorm development is unlikely, but if development occurs, storms may be severe. Zonal mid-level flow will become the dominate flow by midweek next week. With weak mid- level waves traversing the CONUS, will have to maintain at least slight-chance PoPs for the remainder of the period. Muggy conditions will continue for the duration of the period as high temperatures will remain in the low to middle 90s and dewpoints in the 70s. This combination yields Heat Index values near 100 degrees every afternoon of the period. && .AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon) Issued at 1218 PM CDT THU JUL 7 2016 Main concerns in the forecasts are for wind changes as front approaches and passes. Also a chance for strong thunderstorms to develop in eastern Kansas and will need to monitor for possible impact on TOP/FOE. Have added a VCTS thinking storms will be primarily east of terminals. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...67 LONG TERM...Prieto AVIATION...67
Area Forecast Discussion National Weather Service Dodge City KS 229 PM CDT THU JUL 7 2016 ...Updated Short term and Long term discussions... .SHORT TERM...(This evening through Friday) Issued at 227 PM CDT Thu Jul 7 2016 A cold front dropping south across southwest Kansas during the afternoon will be located near the Oklahoma border during the early evening hours. Models are hinting at a weak upper level disturbance approaching from the four corners region early tonight. Given the forecast weak CIN near this boundary, moisture and weak instability ahead of this wave early tonight will retain mention of small chances for convection along and south of the Oklahoma border. Based on some cloud cover overnight and light easterly winds developing the latest MAV/MET guidance looks on track with lows ranging from the mid 60s in west central Kansas to near 75 in south central Kansas and along the Oklahoma border. Cooler, more seasonal temperatures can be expected on Friday given the cooling trend forecast in the 900mb to 850mb level along with the expected cloud cover. Precipitation chances will also be on the increase late day as moisture and lift begins to improve across southwest Kansas. The better opportunity for precipitation will be Friday night. .LONG TERM...(Friday night through Thursday) Issued at 227 PM CDT Thu Jul 7 2016 Warm air advection, moisture, and instability will improve Friday night as another upper level disturbance approaches from the west. Given the 0-1km moisture convergence, CAPES and 0-6km shear there will be a chance for a few of these storms Friday night to become severe. Hail up to half dollar and strong damaging winds will be the main hazard. Heavy rainfall will also be an issue with these storms Friday night given the forecast high precipitable water. Precipitation chances for western Kansas will briefly taper off by Sunday as the warm front lifts north and east and ridging aloft begins to build into the West Central High Plains. Early next week the next upper low/trough will begin to move east across the western United states. As this next system approaches the chance for afternoon and night time convection will begin to increase across western Kansas. A warming trend can also be expected early next week given the warming forecast in the 850mb to 700mb level. The GFS and ECMWF both move this next upper level storm system across the central plains late Tuesday into Wednesday. As this passes a cold front will drop south across western Kansas bringing an end to the warming trend. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1210 PM CDT Thu Jul 7 2016 As a cold front moves south into northern Oklahoma by late day a northerly wind at around 10 knots can be expected at all three taf sites through early tonight. Overnight these north winds will gradually veer to the east which will begin to draw more humid air back into the lower levels. At this time model soundings do not indicate fog or stratus development by 12z Friday but some patchy 3 to 5sm fog does appear possible at GCK and DDC. As the moisture and lift begins to improve early in the day an area of VFR ceilings may begin develop near or just south and west DDC or GCK after 12z. && .PRELIMINARY POINT TEMPS/POPS... DDC 70 92 67 95 / 10 30 30 20 GCK 69 91 67 95 / 10 20 30 20 EHA 68 91 67 97 / 20 20 20 20 LBL 69 94 68 98 / 20 20 30 20 HYS 68 88 66 90 / 20 30 50 20 P28 74 93 71 95 / 20 30 40 20 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Burgert LONG TERM...Burgert AVIATION...Burgert
Area Forecast Discussion National Weather Service Goodland KS 1218 PM MDT THU JUL 7 2016 .SHORT TERM...(Today through Saturday night) Issued at 251 AM MDT Thu Jul 7 2016 Early morning WV imagery and RAP upper level analysis shows a zonal pattern across the Central Rockies with an elongated ridge across the southern plains. A stronger trough is digging into the northern plains from the Northern Rockies. A few weaker shortwave troughs are rotating through the High/Central Plains. Early this morning: A thunderstorm complex that developed late evening/early this morning has transitioned well east of our CWA, however thunderstorm activity has continued to develop where nose of LLJ/WAA interacted with lingering outflow boundary. Trend has been towards activity to diminish in intensity/coverage as it transitions east, and current activity should be outside of our CWA within the next 1-1.5 hr. Pattern could still support isolated thunderstorm redevelopment in our north or east through day break with deep moist flow and elevated CAPE lingering, so timing was adjusted to account for this. Today-Tonight: Shortwave trough in the northern plains has trended faster than earlier guidance had indicated, with 00Z guidance picking up on current trends. With faster trough passage in the northern plains FROPA is now shown to move through our CWA during the day today, with some faster members showing it south of our CWA by midday. This obviously impacts high temps, but also raises the possibility for isolated showers or thunderstorms within the frontal zone if cap were to weaken sufficiently. Guidance does show moisture profiles (above surface) drying out, and this does lower overall confidence at the very least in coverage. Latest trends in short range and high resolution guidance is to keep our CWA dry through most of the day, with better chances late afternoon through the evening as activity along the Cheyenne ridge transitions southeast through the mean flow impacting our north and eventually our east. I also trended Highs downward to account for earlier FROPA. Friday-Saturday night: Initially a post frontal air mass Friday should support highs closer to seasonal normals around 90F. H5 ridge builds into the Plains, with south-southwest flow supporting above normal high temperatures returning Saturday. Pattern still allows for weak shortwave trough passages and Gulf moisture interacting with surface features (mainly lee trough) to produce shower/thunderstorm chances over our CWA through these periods. Guidance continues to show overlapping precip signals, particularly Friday and Saturday evenings. Main uncertainty will be position of surface features that will act as focal points for initiation, followed by evolution of any convective clusters that may develop. 1 to 1.5" PWATs and periods of possible training or slower storm motions could result in elevated flash flood threats, High CAPE values and effective shear in the 30-40kt may also support wind/large hail threats. .LONG TERM...(Sunday through Wednesday) Issued at 251 AM MDT Thu Jul 7 2016 Somewhat unsettled weather is expected during the extended period with intermittent chances for precipitation, along with near seasonal temperatures. On Sunday, upper level ridging progresses eastward from the Plains as an upper closed low moves further over the Pacific Northwest. Southwesterly flow develops aloft across the region, with the ridge over the Upper Midwest and trough over the western CONUS, and moisture filters towards the High Plains. Mainly dry conditions are anticipated. The associated low pressure system over the northern Plains strengthens on Monday as the upper trough advances east. Thunderstorm chances return to the region, with a better chance Monday night when a stronger disturbance passes through the flow. Thunderstorms continue to be possible Tuesday night and Wednesday as another disturbance impacts the High Plains and the upper low makes its way to central Canada, bringing zonal flow to the area. Temperatures in the upper 80s to mid 90s are forecast throughout the period. Lows appear to range within the mid 50s to low 70s. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1109 AM MDT Thu Jul 7 2016 VFR conditions currently expected through the TAF period at GLD and MCK. Moisture pooling ahead of the cold front moving through the central high plains region has led to the development of a ceiling of cumulus, but is expected to mostly dissipate late this afternoon as dryer air moves in behind the front. Later in the day, mostly between 00Z-06Z, but also continuing overnight, there could be isolated thunderstorms and a few lingering overnight showers that track through the region mainly along and north of the Kansas/Nebraska border. Have not included them in the current TAFs as probabilities are low and are not expected to be part of the prevailing conditions at this time. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JBH AVIATION...LOCKHART
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1225 PM CDT THU JUL 7 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 316 AM CDT THU JUL 7 2016 Once again the models have struggled to show where the MCS will track with the ARW and NMM appearing to have some idea of the location but 3 to 4 hours off on the timing. Water vapor imagery shows a synoptic scale upper wave moving into the northern plains while profiler hint at another MCV in eastern NEB. At the surface, low pressure was analyzed over eastern CO and a meso high from this morning`s convection was noted over the mid MO river valley. With the MCS tracking across northeast KS this morning, the forecast is based on the expected outflow pushing into east central KS this morning before retreating back to near the KS river. This boundary could also be reinforced by the late afternoon be synoptic pressure rises from the upper shortwave moving across the northern plains. With this in mind, have highs in the lower 90s across northern KS with mid to upper 90s over east central KS. There is a fair amount of uncertainty in this temp forecast. With the models showing a poor track record with the nocturnal convection, confidence in exactly where the surface boundaries end up is low. As for the possible heat and humidity, there is a concern that I may be a little high with dewpoints this afternoon given the convection overturning the airmass now. Heat indices could be around 105 along and south of the KS river but think I`ll wait to see where the outflow ends up to get a better idea of where a heat advisory may be needed. Precip chances through the afternoon are expected to be low but not zero. Models strengthen the mid level EML with 700MB temps around +17. This would be a substantial cap to a surface parcel. Have held onto some 20 to 30 percent POPs because models bring the surface trough into east central KS which may have enough convergence along it for an isolated storm during the heat of the day. Overnight, the low level jet is progged to be veered to the west southwest so convergence along the boundary would appear to be minimal. So again will only keep a small chance POP. But given the recent track record of the models confidence in the forecast is below average. .LONG TERM...(Friday through Wednesday) Issued at 316 AM CDT THU JUL 7 2016 Friday into the weekend, have kept slight chance POPs south of I-70 for the day on Friday as a stationary boundary should stay set up over southern KS. Weak quasi-zonal to northwest flow will be set up over the region, so as we head into the weekend, there may be some very subtle shortwaves and that advect out of the Northern and Central Rockies vicinity over the region and help provide additional lift over weak surface convergence to spark a few showers and possibly thunderstorms as a conditionally unstable atmosphere sets back up over northeastern KS. Very difficult at this time to eliminate small chance POPs out of any time frame due to possible convection developing in association with this boundary. Most precip would likely be all elevated and weak shear would limit organization. By the end of the weekend, weak ridging builds into the region and late Sunday would probably be a time where precip chances could be lowered in future updates at least looking ahead right now. Mean Westerlies will continue to reside to the north over the northern tier of the CONUS. By Monday, a deepening North Pac Low digs into the Intermountain West and begins to impact the Central Plains Monday night into Tuesday time frame as initial weak lead shortwaves impact northeastern KS area. This brings back a reasonable increase in POPs, but still slight to chance only as coverage isn`t high confidence at this time. Finally, another weak cold front arrives day time frame Tuesday and as the previously mentioned North Pac Low lifts into the Northern Plains and Central Canada, a stationary boundary is left behind and probably gives reasonable chances of off and on precip and some unorganized storms through mid week and could finally exit the region by Thursday. Continued WAA into this time frame should bring dewpoints back into the upper 60s and lower 70s consistently with surface temps into the low to perhaps mid 90s. Heat indices will again likely rise into the low 100s. && .AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon) Issued at 1218 PM CDT THU JUL 7 2016 Main concerns in the forecasts are for wind changes as front approaches and passes. Also a chance for strong thunderstorms to develop in eastern Kansas and will need to monitor for possible impact on TOP/FOE. Have added a VCTS thinking storms will be primarily east of terminals. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Wolters LONG TERM...Drake AVIATION...67
Area Forecast Discussion National Weather Service Dodge City KS 1211 PM CDT THU JUL 7 2016 ...Updated Aviation Discussion... .SYNOPSIS... Issued at 313 AM CDT Thu Jul 7 2016 A shortwave trough will traverse the northern plains today, helping to push a weak cold front through western Kansas by tonight. Moist upslope flow will develop behind the front tonight and then persist into Friday. This surface front will remain over the southern and central plains Saturday as weak upper level ridging moves over the high plains. A large upper level trough over the western United States Saturday and Sunday is expected to progress eastward into the northern plains by Monday. Surface troughing will develop in advance of this upper level system by Sunday, with a weak cold front approaching by late Monday. && .SHORT TERM...(Today and tonight) Issued at 313 AM CDT Thu Jul 7 2016 There is some uncertainty with the speed of the aforementioned cold front today. The RAP is faster with the front with slightly cooler temperatures, while the NAM is a bit slower. The HRRR is also faster. Given that the winds were already from the northeast at Hays and Hill City as of 3 am, which is probably due to thunderstorm outflow from storm clusters in Nebraska, it`s likely that the faster frontal movement is correct. This would result in 100+ temperatures being confined to the Oklahoma state line, with cooler mid 90s or perhaps even lower 90s along Interstate 70. Thunderstorms are not expected although there is a very slight chance along the Colorado state line along the front that will be trailing back to the west-northwest. .LONG TERM...(Friday through Wednesday) Issued at 313 AM CDT Thu Jul 7 2016 There is a chance of thunderstorms on Friday as low level upslope flow results in high theta-e values on the cool side of the front. These could be severe given a belt of 45kt upper level winds and given the expected slow storm motions, resulting in good storm top ventilation. Temperatures will be cooler, with highs only in the lower 90s at best. There is a small chance of thunderstorms into Saturday despite the weak upper level ridging as the frontal boundary lingers. THe aforementioned strong upper level trough developing over the western United States this weekend will result in west-southwesterly mid level flow and lee surface troughing over the high plains by Saturday and persisting into Sunday. There is a small chance of thunderstorm along and ahead of the surface trough, with south winds and warmer maximum temperatures into the mid 90s. As the upper level trough progresses into the northern plains by Monday, a weak cold front should progress into western Kansas, resulting in continued small thunderstorm chances. As long as the southern edge of mid-latitude belt of westerlies remains over Kansas, thunderstorms will be hard to rule out just about any day. This be due to the tendency for surface fronts to stall out across the area, along with low level moisture convergence. Additionally, minor disturbances in the westerlies could enhance thunderstorm chances on certain days. && .AVIATION...(For the 18Z TAFS through 18Z Friday afternoon) Issued at 1210 PM CDT Thu Jul 7 2016 As a cold front moves south into northern Oklahoma by late day a northerly wind at around 10 knots can be expected at all three taf sites through early tonight. Overnight these north winds will gradually veer to the east which will begin to draw more humid air back into the lower levels. At this time model soundings do not indicate fog or stratus development by 12z Friday but some patchy 3 to 5sm fog does appear possible at GCK and DDC. As the moisture and lift begins to improve early in the day an area of VFR ceilings may begin develop near or just south and west DDC or GCK after 12z. && .PRELIMINARY POINT TEMPS/POPS... DDC 98 70 92 67 / 0 10 30 30 GCK 96 69 91 67 / 0 10 20 30 EHA 101 68 91 67 / 10 20 20 20 LBL 101 69 94 68 / 10 20 20 30 HYS 95 68 88 66 / 0 10 30 50 P28 105 74 93 71 / 10 20 30 40 && .DDC Watches/Warnings/Advisories... NONE. && $$ SYNOPSIS...Finch SHORT TERM...Finch LONG TERM...Finch AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
701 AM CDT THU JUL 7 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 316 AM CDT THU JUL 7 2016 Once again the models have struggled to show where the MCS will track with the ARW and NMM appearing to have some idea of the location but 3 to 4 hours off on the timing. Water vapor imagery shows a synoptic scale upper wave moving into the northern plains while profiler hint at another MCV in eastern NEB. At the surface, low pressure was analyzed over eastern CO and a meso high from this morning`s convection was noted over the mid MO river valley. With the MCS tracking across northeast KS this morning, the forecast is based on the expected outflow pushing into east central KS this morning before retreating back to near the KS river. This boundary could also be reinforced by the late afternoon be synoptic pressure rises from the upper shortwave moving across the northern plains. With this in mind, have highs in the lower 90s across northern KS with mid to upper 90s over east central KS. There is a fair amount of uncertainty in this temp forecast. With the models showing a poor track record with the nocturnal convection, confidence in exactly where the surface boundaries end up is low. As for the possible heat and humidity, there is a concern that I may be a little high with dewpoints this afternoon given the convection overturning the airmass now. Heat indices could be around 105 along and south of the KS river but think I`ll wait to see where the outflow ends up to get a better idea of where a heat advisory may be needed. Precip chances through the afternoon are expected to be low but not zero. Models strengthen the mid level EML with 700MB temps around +17. This would be a substantial cap to a surface parcel. Have held onto some 20 to 30 percent POPs because models bring the surface trough into east central KS which may have enough convergence along it for an isolated storm during the heat of the day. Overnight, the low level jet is progged to be veered to the west southwest so convergence along the boundary would appear to be minimal. So again will only keep a small chance POP. But given the recent track record of the models confidence in the forecast is below average. .LONG TERM...(Friday through Wednesday) Issued at 316 AM CDT THU JUL 7 2016 Friday into the weekend, have kept slight chance POPs south of I-70 for the day on Friday as a stationary boundary should stay set up over southern KS. Weak quasi-zonal to northwest flow will be set up over the region, so as we head into the weekend, there may be some very sublte shortwaves and that advect out of the Northern and Central Rockies vicinity over the region and help provide additional lift over weak surface convergence to spark a few showers and possibly thunderstorms as a conditionally unstable atmosphere sets back up over northeastern KS. Very difficult at this time to eliminate small chance POPs out of any time frame due to possible convection developing in association with this boundary. Most precip would likely be all elevated and weak shear would limit organization. By the end of the weekend, weak ridging builds into the region and late Sunday would probably be a time where precip chances could be lowered in future updates at least looking ahead right now. Mean Westerlies will continue to reside to the north over the northern tier of the CONUS. By Monday, a deepening North Pac Low digs into the Intermountain West and begins to impact the Central Plains Monday night into Tuesday time frame as initial weak lead shortwaves impact northeastern KS area. This brings back a reasonable increase in POPs, but still slight to chance only as coverage isn`t high confidence at this time. Finally, another weak cold front arrives day time frame Tuesday and as the previously mentioned North Pac Low lifts into the Northern Plains and Central Canada, a stationary boundary is left behind and probably gives reasonable chances of off and on precip and some unorganized storms through mid week and could finally exit the region by Thursday. Continued WAA into this time frame should bring dewpoints back into the upper 60s and lower 70s consistently with surface temps into the low to perhaps mid 90s. Heat indices will again likely rise into the low 100s. && .AVIATION...(For the 12Z TAFS through 12Z Friday Morning) Issued at 654 AM CDT THU JUL 7 2016 For the 12Z TAFs, ongoing thunderstorms continue to move through the area and over the TAF sites with reasonably good confidence until around mid morning time frame. Conditions improve into the afternoon before FROPA this evening. Until then winds will generally have a southerly...southeasterly component and gust up to the low 20kt range. Winds shift to the northwest after FROPA. Not expecting significant CIG/VIS degradation outside of the TSRA activity. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Wolters LONG TERM...Drake AVIATION...Drake
Area Forecast Discussion National Weather Service Goodland KS 518 AM MDT THU JUL 7 2016 .SHORT TERM...(Today through Saturday night) Issued at 251 AM MDT Thu Jul 7 2016 Early morning WV imagery and RAP upper level analysis shows a zonal pattern across the Central Rockies with an elongated ridge across the southern plains. A stronger trough is digging into the northern plains from the Northern Rockies. A few weaker shortwave troughs are rotating through the High/Central Plains. Early this morning: A thunderstorm complex that developed late evening/early this morning has transitioned well east of our CWA, however thunderstorm activity has continued to develop where nose of LLJ/WAA interacted with lingering outflow boundary. Trend has been towards activity to diminish in intensity/coverage as it transitions east, and current activity should be outside of our CWA within the next 1-1.5 hr. Pattern could still support isolated thunderstorm redevelopment in our north or east through day break with deep moist flow and elevated CAPE lingering, so timing was adjusted to account for this. Today-Tonight: Shortwave trough in the northern plains has trended faster than earlier guidance had indicated, with 00Z guidance picking up on current trends. With faster trough passage in the northern plains FROPA is now shown to move through our CWA during the day today, with some faster members showing it south of our CWA by midday. This obviously impacts high temps, but also raises the possibility for isolated showers or thunderstorms within the frontal zone if cap were to weaken sufficiently. Guidance does show moisture profiles (above surface) drying out, and this does lower overall confidence at the very least in coverage. Latest trends in short range and high resolution guidance is to keep our CWA dry through most of the day, with better chances late afternoon through the evening as activity along the Cheyenne ridge transitions southeast through the mean flow impacting our north and eventually our east. I also trended Highs downward to account for earlier FROPA. Friday-Saturday night: Initially a post frontal air mass Friday should support highs closer to seasonal normals around 90F. H5 ridge builds into the Plains, with south-southwest flow supporting above normal high temperatures returning Saturday. Pattern still allows for weak shortwave trough passages and Gulf moisture interacting with surface features (mainly lee trough) to produce shower/thunderstorm chances over our CWA through these periods. Guidance continues to show overlapping precip signals, particularly Friday and Saturday evenings. Main uncertainty will be position of surface features that will act as focal points for initiation, followed by evolution of any convective clusters that may develop. 1 to 1.5" PWATs and periods of possible training or slower storm motions could result in elevated flash flood threats, High CAPE values and effective shear in the 30-40kt may also support wind/large hail threats. .LONG TERM...(Sunday through Wednesday) Issued at 251 AM MDT Thu Jul 7 2016 Somewhat unsettled weather is expected during the extended period with intermittent chances for precipitation, along with near seasonal temperatures. On Sunday, upper level ridging progresses eastward from the Plains as an upper closed low moves further over the Pacific Northwest. Southwesterly flow develops aloft across the region, with the ridge over the Upper Midwest and trough over the western CONUS, and moisture filters towards the High Plains. Mainly dry conditions are anticipated. The associated low pressure system over the northern Plains strengthens on Monday as the upper trough advances east. Thunderstorm chances return to the region, with a better chance Monday night when a stronger disturbance passes through the flow. Thunderstorms continue to be possible Tuesday night and Wednesday as another disturbance impacts the High Plains and the upper low makes its way to central Canada, bringing zonal flow to the area. Temperatures in the upper 80s to mid 90s are forecast throughout the period. Lows appear to range within the mid 50s to low 70s. && .AVIATION...(For the 12Z TAFS through 12Z Friday morning) Issued at 517 AM MDT Thu Jul 7 2016 Lingering low level moisture associated with weak easterly flow ahead of approaching cold front could support fog/stratus at both KGLD and KMCK terminals this morning. While short range and high resolution guidance does show this increase in low level moisture no guidance is indicating drops below VFR at this time. Confidence is not high enough to indroduce in TAFs at this time. A complication could be the increased mixing from exiting thunderstorm activity east of KMCK and a deparing LLJ preventing fog formation. Will need to monitor, but will hold off on introducing lower condtions at this time. A cold front will pass through the region by midday with at least a brief period (if not 6 hr period) of gusty north winds imediately behind the front, followed by a shift and decrease in winds to the northeast and then east this evening. Isolated thunderstorms may be possible this afternoon/evening (mainly at KMCK), however confidence/coverage is too low to include mention in TAFs at this time. && .GLD Watches/Warnings/Advisories... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...DR LONG TERM...JBH AVIATION...DR
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1150 PM CDT WED JUL 6 2016 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Thursday) Issued at 328 PM CDT WED JUL 6 2016 Effects of northeast and southern KS convection this morning has left airmass over the forecast area drier and not as hot as previously forecast. Thus, have struggled to have HI values approach 100 degrees across most of the area and have cancelled Heat Advisory. Main questions for the forecast for tonight and Thursday are: What will be the mechanism for potential thunderstorms affecting us tonight and Thursday, and whether temps and dewpoints will reach high enough to meet heat index criteria Thursday afternoon? For the latter question, currently forecasting temps in the mid 90s in the north and east with upper 90s possible over portions of central KS. Dewpoints are forecast to range from the lower to possibly middle 70s in the east, while upper 60s to near 70 is more realistic over central KS. This would lead to max HI values from 100 to 105 nearing advisory criteria. However, there is enough uncertainty in reaching these values if we have our airmass once again modified by convective outflows and some cloudiness from overnight/morning thunderstorms near our area. Thus, have not issued an advisory for Thursday and will let midnight forecast crew decide on that as potential convective effects become less uncertain. Water vapor loop shows a weak shortwave trough over extreme western KS, and possibly another one to the northwest in northern CO. Most short and medium range models do not develop persistent convection with these features. However a few runs of the HRRR and experimental HRRR have been developing a cluster of storms over eastern CO or southwest KS and bringing the associated convection across eastern KS after midnight. Given inconsistency of these HRRR runs, have not included any significant POPs from this forecast convection. Possibly more likely scenario would be closer to going forecast, and perhaps best depicted by 12Z NAM, where an MCS is forecast to affect primarily Nebraska, with tail end affecting far northern and northeastern KS late tonight and Thursday morning. This is what has been put in forecast grids, but developments over western KS will obviously have to be monitored for HRRR scenarios. .LONG TERM...(Thursday Night through Wednesday) Issued at 328 PM CDT WED JUL 6 2016 Strong upper wave will move across the Upper Midwest pushing a cold front across the area Thu night. Capping and stronger lift associated with the wave should keep the bulk of the precip NE of the area but will keep low chcs in the northeast given strength of wave. The front will sag into southern KS on Friday and will keep low chcs across the southern counties near the front. By Friday night into the weekend confidence in location and timing of precip is low since recent performance of models has been poor with placement of nocturnal convection. That said chcs would appear to increase at least across central KS Fri night as the thetaE advection increases atop the boundary. The area will remain within the weak upper ridge with overnight storm chcs through the weekend before a unusually strong upper trough moves into the Rockies by early next week. This trough will push a front into the region by later Monday into Tues so it would appear best chcs for organized storms would occur around that time frame. The front will hang up across the area toward mid week and with zonal flow wouldn`t be surprised to see storm chcs persist through next week. && .AVIATION...(For the 06Z TAFS through 06Z Thursday Night) Issued at 1150 PM CDT WED JUL 6 2016 Confidence on convection remains low...too low for inclusion. Thunderstorms to the northwest showing little propagation south but some potential for this as well as isentropic upglide development ahead of it remains. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...GDP LONG TERM...Omitt AVIATION...65 Area Forecast Discussion National Weather Service Little Rock AR 429 AM CDT SAT JUL 9 2016 .SHORT TERM...Today Through Sunday Night Overnight showers and thunderstorms across mainly the northern half of the state brought abundant lightning and localized heavy rainfall to some areas. Will see a southward push in activity through the morning hours which will focus more activity into central Arkansas. Not much has changed in the forecast this morning, with the overall setup still the same. Frontal boundary will situate itself across northern Arkansas and help focus rainfall chances across the state as a shortwave trough makes its way over the area. Track of the shortwave will provide the best rain chances to the northeast half of the state. Start to see a withdraw in rain chances to the east at the end of the short term period as the boundary lifts northward. Temperatures will be a bit cooler across the northern half of the state through the short term with southern areas seeing little reprieve from the heat. && .LONG TERM...Monday Through Friday No big changes will be noted in the extended period. The ridge of high pressure over the southern United States will tend to be strongest in the southwest/southern Plains and weakest over the southeast states. Given this, fronts tracking to the north of the ridge will sag toward the Tennessee Valley, with one such front coming close to northeast Arkansas by the end of the period. For much of the week, any precipitation should be isolated, and it will be hot. While readings will be a little above average, not looking for excessive heat with afternoon heat indices from the mid 90s to just above 100 degrees. As the aforementioned front comes into the picture Thursday/Friday, have better chances for rain. However, looks like most precipitation be be over the northern counties nearest the front, with not much happening in southern Arkansas. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 86 70 88 72 / 60 60 50 30 Camden AR 92 75 93 75 / 30 30 30 20 Harrison AR 84 69 86 70 / 60 50 50 20 Hot Springs AR 92 75 91 75 / 50 30 40 20 Little Rock AR 91 74 91 75 / 60 40 50 30 Monticello AR 91 75 90 76 / 40 30 40 20 Mount Ida AR 91 73 90 74 / 40 30 40 20 Mountain Home AR 85 70 88 71 / 60 60 50 20 Newport AR 88 72 89 73 / 60 60 50 30 Pine Bluff AR 90 74 90 75 / 50 40 50 30 Russellville AR 89 73 90 74 / 60 40 50 20 Searcy AR 89 73 89 73 / 60 50 50 30 Stuttgart AR 89 74 89 75 / 60 40 50 30 && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...226 / Long Term...46
Area Forecast Discussion National Weather Service Little Rock AR 429 AM CDT SAT JUL 9 2016 .SHORT TERM...Today Through Sunday Night Overnight showers and thunderstorms across mainly the northern half of the state brought abundant lightning and localized heavy rainfall to some areas. Will see a southward push in activity through the morning hours which will focus more activity into central Arkansas. Not much has changed in the forecast this morning, with the overall setup still the same. Frontal boundary will situate itself across northern Arkansas and help focus rainfall chances across the state as a shortwave trough makes its way over the area. Track of the shortwave will provide the best rain chances to the northeast half of the state. Start to see a withdraw in rain chances to the east at the end of the short term period as the boundary lifts northward. Temperatures will be a bit cooler across the northern half of the state through the short term with southern areas seeing little reprieve from the heat. && .LONG TERM...Monday Through Friday No big changes will be noted in the extended period. The ridge of high pressure over the southern United States will tend to be strongest in the southwest/southern Plains and weakest over the southeast states. Given this, fronts tracking to the north of the ridge will sag toward the Tennessee Valley, with one such front coming close to northeast Arkansas by the end of the period. For much of the week, any precipitation should be isolated, and it will be hot. While readings will be a little above average, not looking for excessive heat with afternoon heat indices from the mid 90s to just above 100 degrees. As the aforementioned front comes into the picture Thursday/Friday, have better chances for rain. However, looks like most precipitation be be over the northern counties nearest the front, with not much happening in southern Arkansas. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 86 70 88 72 / 60 60 50 30 Camden AR 92 75 93 75 / 30 30 30 20 Harrison AR 84 69 86 70 / 60 50 50 20 Hot Springs AR 92 75 91 75 / 50 30 40 20 Little Rock AR 91 74 91 75 / 60 40 50 30 Monticello AR 91 75 90 76 / 40 30 40 20 Mount Ida AR 91 73 90 74 / 40 30 40 20 Mountain Home AR 85 70 88 71 / 60 60 50 20 Newport AR 88 72 89 73 / 60 60 50 30 Pine Bluff AR 90 74 90 75 / 50 40 50 30 Russellville AR 89 73 90 74 / 60 40 50 20 Searcy AR 89 73 89 73 / 60 50 50 30 Stuttgart AR 89 74 89 75 / 60 40 50 30 && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...226 / Long Term...46
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1219 AM CDT SAT JUL 9 2016 .UPDATE... Updated to include 06z aviation discussion. && .AVIATION... Some SHRA/TSRA will remain possible overnight...generally over portions of central and NRN AR. Have mentioned primarily VCTS as a result...though may have to mentioned in TEMPO or prevailing if potential to impact specific terminals increases. The potential for precip activity will continue through Sat afternoon as well...with some MVFR or lower flight conditions possible. Some patchy fog may also be seen during the morning hrs...especially in areas that see lightest winds combined with recent precip. && .PREV DISCUSSION...(ISSUED 620 PM CDT FRI JUL 8 2016 ) DISCUSSION... Updated to include the 00Z aviation discussion below... AVIATION... Some SHRA/TSRA will continue to be possible during the overnight period...though exact location will be somewhat uncertain. As a result...will just mention some VCTS/VCSH. Chances for precip will remain possible for Sat...with a similar scenario expected regarding coverage and location. Some patchy fog will also be possible...especially across the NRN sites where some precip has been seen recently. PREV DISCUSSION...(ISSUED 305 PM CDT FRI JUL 8 2016) SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1219 AM CDT SAT JUL 9 2016 .UPDATE... Updated to include 06z aviation discussion. && .AVIATION... Some SHRA/TSRA will remain possible overnight...generally over portions of central and NRN AR. Have mentioned primarily VCTS as a result...though may have to mentioned in TEMPO or prevailing if potential to impact specific terminals increases. The potential for precip activity will continue through Sat afternoon as well...with some MVFR or lower flight conditions possible. Some patchy fog may also be seen during the morning hrs...especially in areas that see lightest winds combined with recent precip. && .PREV DISCUSSION...(ISSUED 620 PM CDT FRI JUL 8 2016 ) DISCUSSION... Updated to include the 00Z aviation discussion below... AVIATION... Some SHRA/TSRA will continue to be possible during the overnight period...though exact location will be somewhat uncertain. As a result...will just mention some VCTS/VCSH. Chances for precip will remain possible for Sat...with a similar scenario expected regarding coverage and location. Some patchy fog will also be possible...especially across the NRN sites where some precip has been seen recently. PREV DISCUSSION...(ISSUED 305 PM CDT FRI JUL 8 2016) SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 620 PM CDT FRI JUL 8 2016 .DISCUSSION... Updated to include the 00Z aviation discussion below... && .AVIATION... Some SHRA/TSRA will continue to be possible during the overnight period...though exact location will be somewhat uncertain. As a result...will just mention some VCTS/VCSH. Chances for precip will remain possible for Sat...with a similar scenario expected regarding coverage and location. Some patchy fog will also be possible...especially across the NRN sites where some precip has been seen recently. && .PREV DISCUSSION...(ISSUED 305 PM CDT FRI JUL 8 2016) SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...62
Area Forecast Discussion National Weather Service Little Rock AR 305 PM CDT FRI JUL 8 2016 .SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. && .Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...44 / Long Term...59
Area Forecast Discussion National Weather Service Little Rock AR 112 PM CDT FRI JUL 8 2016 .AVIATION...08/18Z Taf Cycle Remnants from morning MCS now affecting parts of NWRN AR. Expect additional sctd SHRA/TSRA to form this aftn acrs NRN and WRN AR along assocd outflow bndry/s. Have TEMPO groups at KHRO and KBPK this aftn to account for this. Outside of convection...VFR conds wl prevail thru the pd. Cannot rule out some SCTD low clouds again Sat mrng...but moisture lvls not as abundant to mention any CIGS attm. /44/ && .PREV DISCUSSION...(ISSUED 1139 AM CDT FRI JUL 8 2016) UPDATE... Cont to monitor convective trends to our NW this mrng. MCS conts to work EWD this aftn and affect mainly the NRN third of the FA. While an overall weakening trend has been noted...expect storms to refire as we apch max aftn heating. Some sctd SHRA/TSRA has formed in the last hour over parts of W-CNTRL AR in the vcnty of the an assocd outflow bndry and along the SERN periphery of the higher lvl cloud shield. Just made some minor adjustments to POPS this aftn to account for radar/Hi-Res model trends. As expected...high temps ovr N AR wl be held down some by abundant clouds/rain chcs. Cannot rule out a few strong/svr storms this aftn as well...with gusty winds being the main concern. Rest of fcst in good shape. All updates are out. /44/ PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1139 AM CDT FRI JUL 8 2016 .UPDATE... Cont to monitor convective trends to our NW this mrng. MCS conts to work EWD this aftn and affect mainly the NRN third of the FA. While an overall weakening trend has been noted...expect storms to refire as we apch max aftn heating. Some sctd SHRA/TSRA has formed in the last hour over parts of W-CNTRL AR in the vcnty of the an assocd outflow bndry and along the SERN periphery of the higher lvl cloud shield. Just made some minor adjustments to POPS this aftn to account for radar/Hi-Res model trends. As expected...high temps ovr N AR wl be held down some by abundant clouds/rain chcs. Cannot rule out a few strong/svr storms this aftn as well...with gusty winds being the main concern. Rest of fcst in good shape. All updates are out. /44/ && .PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 620 AM CDT FRI JUL 8 2016 .UPDATE... Updated to include 12z aviation discussion. && .AVIATION... Some patchy MVFR 1500-2000ft ceilings possible around central and southern AR terminals the next few hours, then mainly VFR conditions expected. Winds out of the SW today 7-12kts gusting as high as 20kts at times. Could see isolated/scattered SH/TS activity across mainly northern areas this afternoon/evening and then again after midnight. Widespread mid/high clouds will be in place for much of the TAF period as well. && .PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016 ) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion National Weather Service Little Rock AR 354 AM CDT FRI JUL 8 2016 .SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. && .LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 93 74 87 72 / 40 30 50 60 Camden AR 97 77 96 75 / 10 20 30 30 Harrison AR 89 71 84 69 / 50 50 50 50 Hot Springs AR 95 77 92 75 / 20 30 40 30 Little Rock AR 96 78 93 76 / 20 30 40 40 Monticello AR 96 79 95 76 / 10 20 30 30 Mount Ida AR 94 75 92 73 / 20 30 40 30 Mountain Home AR 90 72 85 70 / 50 50 50 60 Newport AR 94 75 88 73 / 40 30 50 50 Pine Bluff AR 95 78 92 75 / 20 20 40 30 Russellville AR 94 76 90 74 / 20 40 50 40 Searcy AR 95 76 91 73 / 20 30 50 50 Stuttgart AR 95 77 92 75 / 20 20 40 40 && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...226 / Long Term...46
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1225 AM CDT FRI JUL 8 2016 .UPDATE... Updated to include 06z aviation discussion. && .AVIATION... Showers and thunderstorms slowly moving SE out of SW MO and SE KS this morning may bring vicinity SH/TS activity to northern AR terminals this morning as they dissipate. Otherwise, MVFR ceilings expected across central/southern AR around daybreak once again with primarily VFR conditions seen otherwise. Winds will be out of the SW again with speeds of 8-12kts and gusts to 20kts at times. && .PREV DISCUSSION...(ISSUED 711 PM CDT THU JUL 7 2016 ) AVIATION...08/00z Taf Cycle Look for VFR conds to cont thru much of pd. Sct-bkn low clouds wl again dvlp toward sunrise Fri...mainly acrs CNTRL and SRN AR... resulting in ocnl MVFR cigs. Hi-Res model data conts to suggest a complex of storms forming forming later tngt acrs SRN KS... eventually working SEWD into parts of NW AR Fri mrng. Included PROB30 groups at KHRO and KBPK to account for any storms that may form along residual small scale bndry`s later in the day. /44/ PREV DISCUSSION...(ISSUED 252 PM CDT THU JUL 7 2016) DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion National Weather Service Little Rock AR 711 PM CDT THU JUL 7 2016 .AVIATION...08/00z Taf Cycle Look for VFR conds to cont thru much of pd. Sct-bkn low clouds wl again dvlp toward sunrise Fri...mainly acrs CNTRL and SRN AR... resulting in ocnl MVFR cigs. Hi-Res model data conts to suggest a complex of storms forming forming later tngt acrs SRN KS... eventually working SEWD into parts of NW AR Fri mrng. Included PROB30 groups at KHRO and KBPK to account for any storms that may form along residual small scale bndry`s later in the day. /44/ && .PREV DISCUSSION...(ISSUED 252 PM CDT THU JUL 7 2016) DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .LZK Watches/Warnings/Advisories... Heat Advisory until 8 PM CDT this evening FOR Arkansas-Bradley- Calhoun-Clark-Cleburne-Cleveland-Conway-Dallas-Desha-Drew- Faulkner-Garland-Grant-Hot Spring-Independence-Jackson-Jefferson- Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery-Ouachita-Perry- Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White- Woodruff-Yell. && $$
Area Forecast Discussion National Weather Service Little Rock AR 252 PM CDT THU JUL 7 2016 .DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. && .SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. && .LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 95 78 94 75 / 40 30 40 30 Camden AR 97 77 96 78 / 20 20 10 20 Harrison AR 93 76 90 72 / 50 20 50 50 Hot Springs AR 96 79 95 77 / 20 20 20 30 Little Rock AR 96 78 96 78 / 20 20 20 30 Monticello AR 96 78 96 79 / 20 20 10 20 Mount Ida AR 95 78 93 75 / 20 20 20 30 Mountain Home AR 95 76 91 73 / 60 30 50 50 Newport AR 95 78 95 76 / 40 30 40 30 Pine Bluff AR 96 77 94 78 / 20 20 20 20 Russellville AR 98 77 94 76 / 30 20 20 40 Searcy AR 96 77 95 76 / 30 20 20 30 Stuttgart AR 96 77 95 78 / 20 20 20 20 && .LZK Watches/Warnings/Advisories... Heat Advisory until 8 PM CDT this evening FOR Arkansas-Bradley- Calhoun-Clark-Cleburne-Cleveland-Conway-Dallas-Desha-Drew- Faulkner-Garland-Grant-Hot Spring-Independence-Jackson-Jefferson- Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery-Ouachita-Perry- Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White- Woodruff-Yell. && $$ Short Term...59 / Long Term...66
Area Forecast Discussion...Updated for Aviation National Weather Service Little Rock AR 1215 PM CDT THU JUL 7 2016 .AVIATION... Overall VFR flight conditions are expected. Patchy MVFR may be seen especially associated with showers or isolated thunderstorms. Winds are expected to be southeast to southwest at 10 to 20 mph with some gusts to around 25 mph in spots. After sunset, winds will lower to 5 to 15 mph. Tonight, isolated convection may be seen over northern Arkansas and affect KHRO and KBPK Tafs. Winds will lower to mainly below 10 mph. (59) && .Prev Discussion.../ Issued 1000 AM CDT THU JUL 7 2016 Earlier update to add scattered convection over northern AR. Complex over MO has helped develop this convection associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR. Will monitor for possible lake wind advisory. Otherwise, temperatures will warm to the 90s today, and with the added humidity, heat index values will reach around 105 degrees. A heat advisory is in effect for most of AR except the northern areas. Late morning update will fine tune convection chances, possibly adding a bit more southern areas in slight chance area. (59) && .PREV DISCUSSION...(ISSUED 358 AM CDT THU JUL 7 2016 SHORT TERM...Today Through Friday Night Similar setup to yesterday across the region with surface high pressure in place to the southeast and low pressure noted across the Southern Plains. Two MCS`s noted across the region with the first impacting Tennessee/Kentucky and the second moving out of SE Nebraska into northeastern Kansas. Should see fewer impacts to the forecast area from upstream MCS in Kansas due to more northerly location and easterly trajectory. Early morning HRRR runs attempt to initiate some shower and thunderstorm activity across E Oklahoma with a weak shortwave in the mean flow and shift this activity toward Arkansas throughout the day. No activity has manifested itself as of 09z so will keep forecast dry attm though wouldn`t be surprised to see at least a few isolated showers develop. SW flow at the surface will be in place again today and winds will be enhanced due to increased pressure gradient. Wind speeds will likely be aoa 12-18mph with gusts as high as 25mph at times. The other notable mention of the day goes to heat index values across the state. With dewpoints in the 70s and temps cranking into the mid to upper 90s, another run at heat index values of 105 will be made this afternoon. Rain chances will be in place across mainly northern Arkansas on Friday as a surface boundary approaches from the NW. Additionally, the H500 pattern begins to show signs of transitioning to more of an active period with more of a NW flow expected. Will have to keep an eye on temps/heat indices Friday as heat indices could approach heat advisory levels once again across the southern half of the state. Could see chances for a more notable thunderstorm complex approaching the state from the northwest late Friday night. LONG TERM...Saturday Through Wednesday As a ridge of high pressure weakens over the southeast United States, a cold front will be allowed to drop through the Ohio and Tennessee Valleys during the upcoming weekend. The front may actually make it into northeast Arkansas. Isolated to scattered showers and thunderstorms are in the forecast. Given more clouds, it will be slightly cooler. A few storms may be severe as the front nears the region. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected at this point. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will be noted out west. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. Readings may be a touch below average toward the Missouri border this weekend near the aforementioned front. && .LZK Watches/Warnings/Advisories... Heat Advisory from 10 AM this morning to 8 PM CDT this evening FOR Arkansas-Bradley-Calhoun-Clark-Cleburne-Cleveland-Conway- Dallas-Desha-Drew-Faulkner-Garland-Grant-Hot Spring-Independence- Jackson-Jefferson-Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery- Ouachita-Perry-Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White-Woodruff-Yell. && $$ Aviation...226
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
333 AM CDT SAT JUL 9 2016 .SHORT TERM...(Today and Tonight) Issued at 322 AM CDT SAT JUL 9 2016 A broad upper level ridge will move east across the central and southern plains Today and Tonight. Early this morning an area of elevated thunderstorms were developing across southeast NE due to weak isentropic lift. These storms were back building to the northwest but were slowly shifting southeast. The north central and northeast counties may see an isolated thunderstorm during the morning hours. Today and Tonight, most numerical models show any weak outflow boundaries washing out through the day. The WRF, HRRR and RAP models show the potential for a few elevated thunderstorms this morning across the CWA but these should diminish as the boundary layer mixes deeper. The WRF solutions along with the HRRR forecast isolated thunderstorms to develop across portions of east central and early this evening across portions of northeast and east central KS ahead of minor MCV that develops across northeast NE this morning and tracks southeast. There is a very weak cap so any type of minor ascent could cause a few isolated storms to develop during the late afternoon and into the early evening hours. The remainder of the night will remain dry. Highs Today will reach the upper 80s to mid 90s. Surface dewpoints will remain in the lower to mid 70s through the afternoon hours which will cause heat indices to rise into the mid 90s to around 100 degrees. .LONG TERM...(Sunday through Friday) Issued at 322 AM CDT SAT JUL 9 2016 Sunday afternoon and much of Monday should remain dry with a mid to upper ridge advecting overhead. Should mix to around the 800mb level on both days which should help our temps to rise into the mid 90s. With ample sunshine and dewpoints in the upper 60s and low 70s, heat index values will be hot but should remain under advisory level criteria. Winds will likely increase ahead of the deepening North Pac Low as it advects into the Northern Plains region. This system leaves questions about what type of weather we see late Monday evening into Tuesday morning and how much. ECMWF and GFS are coming into good agreement on positioning of major features, but the NAM is slowing the arrival of the cold boundary perhaps lifting the overall system to a more northerly track quicker. Regardless, at this time, it is hard to say with great certainty on what specific type of storms will occur and coverage. Better large scale ascent is focused to the north of the CWA. Overall hint is that the cold push is modified and slows down as it enters the Central Plains. This system eventually sets up a stationary boundary across the region that allows for precip chances off and on the bulk of the week ahead. But for Monday night into Tuesday, storms may have a hard time getting going initially as the 700mb level temps seem to be at or above 12C. Additionally, if the cold push is weak, then with weak forcing, it may be too hard to get storms to form this far south until later into the night as a LLJ noses into the area. Perhaps storms become are more elevated and form a complex that then propagates east with time. Then into the day on Tuesday better shear profiles seem to take shape for the rest of the period. With a transition in the upper levels to a quasi-zonal to northwesterly flow regime, there could be periods where storm chances are greater through at least Thursday, but hard to pinpoint at this time with any shortwave advecting overhead. Bottom line, some storms could be strong to severe given a conditionally unstable environment in place. High temps remain in the 90s with no strong advection either way in place for any prolonged period of time. && .AVIATION...(For the 06Z TAFS through 06Z Saturday Night) Issued at 1142 PM CDT FRI JUL 8 2016 VFR conditions are expected through the period outside of any convective activity. Chances at the terminals are low for tsra for inclusion at this time. Winds light east becoming southeast around 10 kts by 15Z. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...Drake AVIATION...53
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1142 PM CDT FRI JUL 8 2016 ...Update to aviation forecast discussion... .SHORT TERM...(This Evening through Saturday) Issued at 256 PM CDT FRI JUL 8 2016 Despite some morning clouds and an easterly wind across the area, temperatures have risen into the upper 80s to near 90, save the far south which is still holding in the lower 80s as clouds continue there. Several small waves noted in the flow, one of which is approaching central kansas at this hour. Experimental HRRR has a relatively reasonable solution that brings the MCV into the CWA and interacts with an outflow moving up from the south out of earlier convection, and brings a round of showers and thunderstorms across western and southern areas later this afternoon into the evening. Wind fields are weak, although CAPE could be enough to generate some wind with storms that develop. LLJ is only around 25kts overnight, but may redevelop storms over central/south central Kansas overnight and move eastward across mainly our southern counties. Only carrying slight chance to low chance PoPs given coverage and uncertainty. Lows tonight forecast near 70 with highs on Saturday in the upper 80s to low 90s. .LONG TERM...(Saturday Night through Friday) Issued at 256 PM CDT FRI JUL 8 2016 No major changes made in the extended with still some variances in model guidance on timing and coverage of precipitation. Best chances for seeing more widespread showers and thunderstorms will be with the arrival of a cold front on Tuesday. More details below. Temporary ridging aloft Saturday night and Sunday should keep much of the area dry. Strong upper trough across the Inter Mountain West deepens a lee trough over the Rockies Sunday and Monday, increasing southerly winds at 10 to 15 mph sustained in the afternoon. Gusts up to 30 mph are possible, alleviating slightly the hot and humid conditions with readings in the lower and middle 90s. The aforementioned upper trough ejects over the northern plains Monday evening and Tuesday, surging the cold front into north central KS in the overnight hours. Guidance continues to exhibit high confidence in this scenario and have raised pops into the likely category near the KS and NE border. Ample mixed layer CAPE and effective shear parameters near 40 kts could develop a few strong to severe storms over north central areas. This activity pushes south and east on Tuesday, spreading chances towards the entire CWA. Models differ some Tuesday evening onward as the frontal boundary hangs up across the area. Subtle impulses embedded within the northwesterly flow aloft signals multiple rounds of thunderstorms, especially on Wednesday evening. Temps hover near normal values in the lower 90s for highs and low 70s for overnight lows, likely to drop into the 80s by the end of the period as the frontal boundary shifts south of the area. && .AVIATION...(For the 06Z TAFS through 06Z Saturday Night) Issued at 1142 PM CDT FRI JUL 8 2016 VFR conditions are expected through the period outside of any convective activity. Chances at the terminals are low for tsra for inclusion at this time. Winds light east becoming southeast around 10 kts by 15Z. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...67 LONG TERM...Prieto AVIATION...53 Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 633 AM CDT SAT JUL 9 2016 .UPDATE... Updated to include 12z aviation discussion. && .AVIATION... Primarily VFR conditions expected through the TAF period with only brief reductions in conditions due to any localized thunderstorm activity. Isolated to scattered showers and thunderstorms will periodically affect terminals with potential for brief wind gusts and heavy rain. Otherwise, overcast mid/high clouds expected with light SW winds that will be variable at times. && .PREV DISCUSSION...(ISSUED 429 AM CDT SAT JUL 9 2016 ) SHORT TERM...Today Through Sunday Night Overnight showers and thunderstorms across mainly the northern half of the state brought abundant lightning and localized heavy rainfall to some areas. Will see a southward push in activity through the morning hours which will focus more activity into central Arkansas. Not much has changed in the forecast this morning, with the overall setup still the same. Frontal boundary will situate itself across northern Arkansas and help focus rainfall chances across the state as a shortwave trough makes its way over the area. Track of the shortwave will provide the best rain chances to the northeast half of the state. Start to see a withdraw in rain chances to the east at the end of the short term period as the boundary lifts northward. Temperatures will be a bit cooler across the northern half of the state through the short term with southern areas seeing little reprieve from the heat. LONG TERM...Monday Through Friday No big changes will be noted in the extended period. The ridge of high pressure over the southern United States will tend to be strongest in the southwest/southern Plains and weakest over the southeast states. Given this, fronts tracking to the north of the ridge will sag toward the Tennessee Valley, with one such front coming close to northeast Arkansas by the end of the period. For much of the week, any precipitation should be isolated, and it will be hot. While readings will be a little above average, not looking for excessive heat with afternoon heat indices from the mid 90s to just above 100 degrees. As the aforementioned front comes into the picture Thursday/Friday, have better chances for rain. However, looks like most precipitation be be over the northern counties nearest the front, with not much happening in southern Arkansas. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 633 AM CDT SAT JUL 9 2016 .UPDATE... Updated to include 12z aviation discussion. && .AVIATION... Primarily VFR conditions expected through the TAF period with only brief reductions in conditions due to any localized thunderstorm activity. Isolated to scattered showers and thunderstorms will periodically affect terminals with potential for brief wind gusts and heavy rain. Otherwise, overcast mid/high clouds expected with light SW winds that will be variable at times. && .PREV DISCUSSION...(ISSUED 429 AM CDT SAT JUL 9 2016 ) SHORT TERM...Today Through Sunday Night Overnight showers and thunderstorms across mainly the northern half of the state brought abundant lightning and localized heavy rainfall to some areas. Will see a southward push in activity through the morning hours which will focus more activity into central Arkansas. Not much has changed in the forecast this morning, with the overall setup still the same. Frontal boundary will situate itself across northern Arkansas and help focus rainfall chances across the state as a shortwave trough makes its way over the area. Track of the shortwave will provide the best rain chances to the northeast half of the state. Start to see a withdraw in rain chances to the east at the end of the short term period as the boundary lifts northward. Temperatures will be a bit cooler across the northern half of the state through the short term with southern areas seeing little reprieve from the heat. LONG TERM...Monday Through Friday No big changes will be noted in the extended period. The ridge of high pressure over the southern United States will tend to be strongest in the southwest/southern Plains and weakest over the southeast states. Given this, fronts tracking to the north of the ridge will sag toward the Tennessee Valley, with one such front coming close to northeast Arkansas by the end of the period. For much of the week, any precipitation should be isolated, and it will be hot. While readings will be a little above average, not looking for excessive heat with afternoon heat indices from the mid 90s to just above 100 degrees. As the aforementioned front comes into the picture Thursday/Friday, have better chances for rain. However, looks like most precipitation be be over the northern counties nearest the front, with not much happening in southern Arkansas. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion National Weather Service Little Rock AR 429 AM CDT SAT JUL 9 2016 .SHORT TERM...Today Through Sunday Night Overnight showers and thunderstorms across mainly the northern half of the state brought abundant lightning and localized heavy rainfall to some areas. Will see a southward push in activity through the morning hours which will focus more activity into central Arkansas. Not much has changed in the forecast this morning, with the overall setup still the same. Frontal boundary will situate itself across northern Arkansas and help focus rainfall chances across the state as a shortwave trough makes its way over the area. Track of the shortwave will provide the best rain chances to the northeast half of the state. Start to see a withdraw in rain chances to the east at the end of the short term period as the boundary lifts northward. Temperatures will be a bit cooler across the northern half of the state through the short term with southern areas seeing little reprieve from the heat. && .LONG TERM...Monday Through Friday No big changes will be noted in the extended period. The ridge of high pressure over the southern United States will tend to be strongest in the southwest/southern Plains and weakest over the southeast states. Given this, fronts tracking to the north of the ridge will sag toward the Tennessee Valley, with one such front coming close to northeast Arkansas by the end of the period. For much of the week, any precipitation should be isolated, and it will be hot. While readings will be a little above average, not looking for excessive heat with afternoon heat indices from the mid 90s to just above 100 degrees. As the aforementioned front comes into the picture Thursday/Friday, have better chances for rain. However, looks like most precipitation be be over the northern counties nearest the front, with not much happening in southern Arkansas. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 86 70 88 72 / 60 60 50 30 Camden AR 92 75 93 75 / 30 30 30 20 Harrison AR 84 69 86 70 / 60 50 50 20 Hot Springs AR 92 75 91 75 / 50 30 40 20 Little Rock AR 91 74 91 75 / 60 40 50 30 Monticello AR 91 75 90 76 / 40 30 40 20 Mount Ida AR 91 73 90 74 / 40 30 40 20 Mountain Home AR 85 70 88 71 / 60 60 50 20 Newport AR 88 72 89 73 / 60 60 50 30 Pine Bluff AR 90 74 90 75 / 50 40 50 30 Russellville AR 89 73 90 74 / 60 40 50 20 Searcy AR 89 73 89 73 / 60 50 50 30 Stuttgart AR 89 74 89 75 / 60 40 50 30 && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...226 / Long Term...46
Area Forecast Discussion National Weather Service Little Rock AR 429 AM CDT SAT JUL 9 2016 .SHORT TERM...Today Through Sunday Night Overnight showers and thunderstorms across mainly the northern half of the state brought abundant lightning and localized heavy rainfall to some areas. Will see a southward push in activity through the morning hours which will focus more activity into central Arkansas. Not much has changed in the forecast this morning, with the overall setup still the same. Frontal boundary will situate itself across northern Arkansas and help focus rainfall chances across the state as a shortwave trough makes its way over the area. Track of the shortwave will provide the best rain chances to the northeast half of the state. Start to see a withdraw in rain chances to the east at the end of the short term period as the boundary lifts northward. Temperatures will be a bit cooler across the northern half of the state through the short term with southern areas seeing little reprieve from the heat. && .LONG TERM...Monday Through Friday No big changes will be noted in the extended period. The ridge of high pressure over the southern United States will tend to be strongest in the southwest/southern Plains and weakest over the southeast states. Given this, fronts tracking to the north of the ridge will sag toward the Tennessee Valley, with one such front coming close to northeast Arkansas by the end of the period. For much of the week, any precipitation should be isolated, and it will be hot. While readings will be a little above average, not looking for excessive heat with afternoon heat indices from the mid 90s to just above 100 degrees. As the aforementioned front comes into the picture Thursday/Friday, have better chances for rain. However, looks like most precipitation be be over the northern counties nearest the front, with not much happening in southern Arkansas. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 86 70 88 72 / 60 60 50 30 Camden AR 92 75 93 75 / 30 30 30 20 Harrison AR 84 69 86 70 / 60 50 50 20 Hot Springs AR 92 75 91 75 / 50 30 40 20 Little Rock AR 91 74 91 75 / 60 40 50 30 Monticello AR 91 75 90 76 / 40 30 40 20 Mount Ida AR 91 73 90 74 / 40 30 40 20 Mountain Home AR 85 70 88 71 / 60 60 50 20 Newport AR 88 72 89 73 / 60 60 50 30 Pine Bluff AR 90 74 90 75 / 50 40 50 30 Russellville AR 89 73 90 74 / 60 40 50 20 Searcy AR 89 73 89 73 / 60 50 50 30 Stuttgart AR 89 74 89 75 / 60 40 50 30 && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...226 / Long Term...46
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1219 AM CDT SAT JUL 9 2016 .UPDATE... Updated to include 06z aviation discussion. && .AVIATION... Some SHRA/TSRA will remain possible overnight...generally over portions of central and NRN AR. Have mentioned primarily VCTS as a result...though may have to mentioned in TEMPO or prevailing if potential to impact specific terminals increases. The potential for precip activity will continue through Sat afternoon as well...with some MVFR or lower flight conditions possible. Some patchy fog may also be seen during the morning hrs...especially in areas that see lightest winds combined with recent precip. && .PREV DISCUSSION...(ISSUED 620 PM CDT FRI JUL 8 2016 ) DISCUSSION... Updated to include the 00Z aviation discussion below... AVIATION... Some SHRA/TSRA will continue to be possible during the overnight period...though exact location will be somewhat uncertain. As a result...will just mention some VCTS/VCSH. Chances for precip will remain possible for Sat...with a similar scenario expected regarding coverage and location. Some patchy fog will also be possible...especially across the NRN sites where some precip has been seen recently. PREV DISCUSSION...(ISSUED 305 PM CDT FRI JUL 8 2016) SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1219 AM CDT SAT JUL 9 2016 .UPDATE... Updated to include 06z aviation discussion. && .AVIATION... Some SHRA/TSRA will remain possible overnight...generally over portions of central and NRN AR. Have mentioned primarily VCTS as a result...though may have to mentioned in TEMPO or prevailing if potential to impact specific terminals increases. The potential for precip activity will continue through Sat afternoon as well...with some MVFR or lower flight conditions possible. Some patchy fog may also be seen during the morning hrs...especially in areas that see lightest winds combined with recent precip. && .PREV DISCUSSION...(ISSUED 620 PM CDT FRI JUL 8 2016 ) DISCUSSION... Updated to include the 00Z aviation discussion below... AVIATION... Some SHRA/TSRA will continue to be possible during the overnight period...though exact location will be somewhat uncertain. As a result...will just mention some VCTS/VCSH. Chances for precip will remain possible for Sat...with a similar scenario expected regarding coverage and location. Some patchy fog will also be possible...especially across the NRN sites where some precip has been seen recently. PREV DISCUSSION...(ISSUED 305 PM CDT FRI JUL 8 2016) SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 620 PM CDT FRI JUL 8 2016 .DISCUSSION... Updated to include the 00Z aviation discussion below... && .AVIATION... Some SHRA/TSRA will continue to be possible during the overnight period...though exact location will be somewhat uncertain. As a result...will just mention some VCTS/VCSH. Chances for precip will remain possible for Sat...with a similar scenario expected regarding coverage and location. Some patchy fog will also be possible...especially across the NRN sites where some precip has been seen recently. && .PREV DISCUSSION...(ISSUED 305 PM CDT FRI JUL 8 2016) SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...62
Area Forecast Discussion National Weather Service Little Rock AR 305 PM CDT FRI JUL 8 2016 .SHORT TERM...Tonight through Saturday Night Sctd SHRA/TSRA have rapidly formed acrs parts of N-CNTRL and NERN AR this aftn...assocd with MCV that worked into NW AR earlier in the day. Severe t-storm watch in effect for those areas until 9 pm tngt. Have adjusted POPS accordingly to reflect current trends...with dcrsg coverage expected later this evening as the upr energy shifts away fm the FA. Upr rdg is fcst to contract ovr the FA heading into weekend... allowing a series of upr impulses to move SEWD acrs AR. This wl result in several more convective complexes to form upstream and eventually affect the region. Timing and coverage of each sys wl be the main fcst concern. Still expect to see the best chcs acrs the NERN half of the FA thru Sat ngt. Rainfall amts upwards of an inch or two can be expected ovr NRN AR...with lesser chcs the further S you go. Rain and clouds wl hold down high temps ovr NRN and parts of CNTRL AR...with the warmest readings in the SRN part of the CWA. && .Long Term...Sunday Through Friday The extended forecast will start with rain in the forecast with the nearly stalled frontal boundary over AR. The best chances will be over central and northern AR on Sunday, then as the boundary is expected to lift northward on Monday, a lower chance and more in the east to northeast will be seen. On Tuesday and much of the rest of the week, a more isolated afternoon to evening chance of convection will be seen during the heat of the day...as the upper high pressure ridge builds more into the Plains and caps some of the potential. The overall chance of strong to severe storms will be low and isolated. Otherwise...Temperatures will generally run above normal values...as humidity levels remain high. Heat index values will also remain in the 90s to 100 degrees to around 105 most days. && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...44 / Long Term...59
Area Forecast Discussion National Weather Service Little Rock AR 112 PM CDT FRI JUL 8 2016 .AVIATION...08/18Z Taf Cycle Remnants from morning MCS now affecting parts of NWRN AR. Expect additional sctd SHRA/TSRA to form this aftn acrs NRN and WRN AR along assocd outflow bndry/s. Have TEMPO groups at KHRO and KBPK this aftn to account for this. Outside of convection...VFR conds wl prevail thru the pd. Cannot rule out some SCTD low clouds again Sat mrng...but moisture lvls not as abundant to mention any CIGS attm. /44/ && .PREV DISCUSSION...(ISSUED 1139 AM CDT FRI JUL 8 2016) UPDATE... Cont to monitor convective trends to our NW this mrng. MCS conts to work EWD this aftn and affect mainly the NRN third of the FA. While an overall weakening trend has been noted...expect storms to refire as we apch max aftn heating. Some sctd SHRA/TSRA has formed in the last hour over parts of W-CNTRL AR in the vcnty of the an assocd outflow bndry and along the SERN periphery of the higher lvl cloud shield. Just made some minor adjustments to POPS this aftn to account for radar/Hi-Res model trends. As expected...high temps ovr N AR wl be held down some by abundant clouds/rain chcs. Cannot rule out a few strong/svr storms this aftn as well...with gusty winds being the main concern. Rest of fcst in good shape. All updates are out. /44/ PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1139 AM CDT FRI JUL 8 2016 .UPDATE... Cont to monitor convective trends to our NW this mrng. MCS conts to work EWD this aftn and affect mainly the NRN third of the FA. While an overall weakening trend has been noted...expect storms to refire as we apch max aftn heating. Some sctd SHRA/TSRA has formed in the last hour over parts of W-CNTRL AR in the vcnty of the an assocd outflow bndry and along the SERN periphery of the higher lvl cloud shield. Just made some minor adjustments to POPS this aftn to account for radar/Hi-Res model trends. As expected...high temps ovr N AR wl be held down some by abundant clouds/rain chcs. Cannot rule out a few strong/svr storms this aftn as well...with gusty winds being the main concern. Rest of fcst in good shape. All updates are out. /44/ && .PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 620 AM CDT FRI JUL 8 2016 .UPDATE... Updated to include 12z aviation discussion. && .AVIATION... Some patchy MVFR 1500-2000ft ceilings possible around central and southern AR terminals the next few hours, then mainly VFR conditions expected. Winds out of the SW today 7-12kts gusting as high as 20kts at times. Could see isolated/scattered SH/TS activity across mainly northern areas this afternoon/evening and then again after midnight. Widespread mid/high clouds will be in place for much of the TAF period as well. && .PREV DISCUSSION...(ISSUED 354 AM CDT FRI JUL 8 2016 ) SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion National Weather Service Little Rock AR 354 AM CDT FRI JUL 8 2016 .SHORT TERM...Today Through Saturday Night Once again, surface analysis indicates ridge of high pressure located southeast of the state with low pressure situated over the TX/OK panhandles. A frontal boundary stretches from the TX/OK panhandles northeastward toward Chicago. Several series of thunderstorm complexes can be seen on NWS radar network early this morning, from northern Oklahoma into southern Kansas as well as across northern Arkansas into southern Missouri. Better rain chances will be in the forecast during the short term period as the upper ridge across the southern US begins to retreat westward a bit providing more of a NW flow aloft over the state. Several upper level shortwave troughs will move along this flow and interact with the boundary at the surface which will be positioned across northern Arkansas the next few days. Potential is there for remnant thunderstorm complexes to move over the state Saturday and Sunday morning, similar to what has been seen across Kansas and Missouri the last few days. Even with rainfall chances in the forecast and more widespread cloud cover noted, only northern Arkansas will see a legitimate break from summertime heat. It will still be quite warm across central and southern areas. Winds will be enhanced again today with breezy conditions out of the southwest. Even lighter winds expected Saturday. && .LONG TERM...Sunday Through Thursday A weakness in the ridge of high pressure over the southeast United States coupled with a storm system aloft over southern Missouri will yield isolated to scattered showers and thunderstorms in Arkansas Sunday. At the surface, a weak stationary front will be draped across northeast sections of the state, which is close to the periphery of the ridge. Precipitation coverage will be greatest north/east of Little Rock nearest the front. A few storms may be severe. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will wobble from the Rockies to the upper Midwest. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. As the period begins, readings may be a touch below average toward the Missouri border near the aforementioned front. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 93 74 87 72 / 40 30 50 60 Camden AR 97 77 96 75 / 10 20 30 30 Harrison AR 89 71 84 69 / 50 50 50 50 Hot Springs AR 95 77 92 75 / 20 30 40 30 Little Rock AR 96 78 93 76 / 20 30 40 40 Monticello AR 96 79 95 76 / 10 20 30 30 Mount Ida AR 94 75 92 73 / 20 30 40 30 Mountain Home AR 90 72 85 70 / 50 50 50 60 Newport AR 94 75 88 73 / 40 30 50 50 Pine Bluff AR 95 78 92 75 / 20 20 40 30 Russellville AR 94 76 90 74 / 20 40 50 40 Searcy AR 95 76 91 73 / 20 30 50 50 Stuttgart AR 95 77 92 75 / 20 20 40 40 && .LZK Watches/Warnings/Advisories...NONE. && $$ Short Term...226 / Long Term...46
Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1225 AM CDT FRI JUL 8 2016 .UPDATE... Updated to include 06z aviation discussion. && .AVIATION... Showers and thunderstorms slowly moving SE out of SW MO and SE KS this morning may bring vicinity SH/TS activity to northern AR terminals this morning as they dissipate. Otherwise, MVFR ceilings expected across central/southern AR around daybreak once again with primarily VFR conditions seen otherwise. Winds will be out of the SW again with speeds of 8-12kts and gusts to 20kts at times. && .PREV DISCUSSION...(ISSUED 711 PM CDT THU JUL 7 2016 ) AVIATION...08/00z Taf Cycle Look for VFR conds to cont thru much of pd. Sct-bkn low clouds wl again dvlp toward sunrise Fri...mainly acrs CNTRL and SRN AR... resulting in ocnl MVFR cigs. Hi-Res model data conts to suggest a complex of storms forming forming later tngt acrs SRN KS... eventually working SEWD into parts of NW AR Fri mrng. Included PROB30 groups at KHRO and KBPK to account for any storms that may form along residual small scale bndry`s later in the day. /44/ PREV DISCUSSION...(ISSUED 252 PM CDT THU JUL 7 2016) DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...226
Area Forecast Discussion National Weather Service Little Rock AR 711 PM CDT THU JUL 7 2016 .AVIATION...08/00z Taf Cycle Look for VFR conds to cont thru much of pd. Sct-bkn low clouds wl again dvlp toward sunrise Fri...mainly acrs CNTRL and SRN AR... resulting in ocnl MVFR cigs. Hi-Res model data conts to suggest a complex of storms forming forming later tngt acrs SRN KS... eventually working SEWD into parts of NW AR Fri mrng. Included PROB30 groups at KHRO and KBPK to account for any storms that may form along residual small scale bndry`s later in the day. /44/ && .PREV DISCUSSION...(ISSUED 252 PM CDT THU JUL 7 2016) DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .LZK Watches/Warnings/Advisories... Heat Advisory until 8 PM CDT this evening FOR Arkansas-Bradley- Calhoun-Clark-Cleburne-Cleveland-Conway-Dallas-Desha-Drew- Faulkner-Garland-Grant-Hot Spring-Independence-Jackson-Jefferson- Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery-Ouachita-Perry- Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White- Woodruff-Yell. && $$
Area Forecast Discussion National Weather Service Little Rock AR 252 PM CDT THU JUL 7 2016 .DISCUSSION... Main concerns in this forecast cycle are chances of convection each day, and if any would be strong to severe storm. Also due to heat and humidity, heat advisories may be needed. Earlier convection over northern AR associated with MCV moved through southern MO and is now well east. It did develop isolated convection to as far south as central AR. Also, the convection was associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR have been seen today, but have overall remained below lake wind advisory levels. Temperatures have made it to the 90s today over central to southern AR, while 70s to 80s over the convection areas of northern AR. Heat index values have reached from 100 to around 105 degrees over most locations. && .SHORT TERM...Today Through Friday Night Forecast will start with a chance to slight chance of late afternoon to evening convection over northern to central AR. After sunset, all convection is expected to weaken and dissipate. Late tonight, a frontal boundary is forecast to sag southeastward toward AR, and chances of convection come back in the forecast for mainly northern areas Friday, then the northern half on Saturday. Also at this time, due to in-place moisture and instability, along with some lift, SPC has issued a marginal to slight risk of severe storms for the northern half of AR. Damaging winds and large hail will be the primary threats. Temperatures on Friday will be similar to Thursday, but heat index values are only around 105 in spots. At this time will hold off on any advisory for Friday. Likewise, surface wind speeds will remain elevated on Friday, but as the front sags south, gradient will be not as likely to reach lake wind advisory levels. && .LONG TERM...Saturday Through Thursday Saturday and Sunday... Model guidance is consistent in indicating that a weak shortwave trough will move southeast towards Arkansas on Saturday...spreading weak large scale forcing for ascent over southern Missouri and northern Arkansas Saturday afternoon. In addition to supplying some weak large scale ascent...this trough is likely to force the persistent baroclinic zone/nearly stationary front currently located near a Kansas City to Paducah line to the southwest towards northern Arkansas. Forecast guidance indicates that a ridge of low-level theta-e will consolidate along this stationary front as it will effectively act like a deformation zone in the low-level flow field with the axis of convective enhancement oriented along the axis of the frontal boundary. This flow field configuration should keep a steady supply of warm and humid air flowing into this theta-e ridge throughout the day on Saturday...setting the stage for a favorable corridor for scattered to numerous thunderstorms from Saturday through Saturday evening. This corridor of storms is likely to remain focused along the Missouri/Arkansas border...however the more storms that develop along the boundary...the higher the potential for the boundary to sag farther south on Saturday. Went ahead with 40-60 POPS from northern to central Arkansas on Saturday to account for this set up. This type of environment supports a threat for flash flooding...however at this time the forcing looks a bit to weak to consider a flash flood watch. Will watch the evolution of this environment closely in the coming days. The largest source of uncertainty for this forecast period is what will happen to the shortwave trough on Sunday into Sunday night. Forecast model guidance indicates that the upper trough will intensify (depending on where you look) and almost become a cut off low by Sunday afternoon over the MO/AR border. The intensification of this trough may not take place though the strength of this trough appears to be dependent upon diabatic contributions which convective parameterizing models can struggle with when the primary diabatic contributer is latent heat release from convection. Taking a vertical cross section through the model depiction of the cut off low reveals a potential vorticity distribution characterized by a sudden intensification in mid-level PV and a sudden decrease in PV at the tropopause level. This signal is a classic depiction of the creation/destruction cycle of PV associated with latent heat release in the troposphere. It is certainly possible that the models are right with this forecast...but this process essentially means that a large and sustained cluster of convection is responsible for intensifying the "upper" trough. If that convection is misplaced or weaker than expected it will have a dramatic effect on the remainder of the forecast as the upper level trough will actually be much farther downstream. Because the boundary is expected to remain quasi-stationary on Sunday...favored the GFS forecast for an intensifying mid-level PV anomaly/trough with this forecast and kept POPs high across northern and central Arkansas on Sunday. Keep in mind that if convection is not as extensive or long-lived on Saturday that the Sunday convection will likely be displaced pretty far off to the southeast on Sunday. At any rate...the NAM/GFS/ECMWF all offer up a similar type of dynamic solution this weekend...with slight differences in timing and intensity of course. Assuming these models are accurate...another round of scattered to numerous showers and thunderstorms are likely across central and northern Arkansas Sunday into Sunday night. Monday through Thursday... With quite a bit of uncertainty in the forecast just this weekend... the forecast for showers and thunderstorms across Arkansas on Monday is fairly low at this time. The shortwave trough/mid-level PV anomaly should have moved east or southeast of Arkansas by Monday...so anticipate that the coverage of any showers or storms will be much lower on Monday compared to this weekend. If the boundary remains in tact this feature by itself could set off a focused area of showers and storms Monday afternoon. Kept POPs in the 20 to 30 percent range for now on Monday with highest confidence in the upper trough being off to the east limiting the coverage of precipitation. The remainder of the week looks to remain warm with low rain chances each day. Kept POPs in the 10 to 20 percent range each day for now with no synoptic features evident in the forecast near Arkansas for the middle of next week. && .PRELIMINARY POINT TEMPS/POPS... Batesville AR 95 78 94 75 / 40 30 40 30 Camden AR 97 77 96 78 / 20 20 10 20 Harrison AR 93 76 90 72 / 50 20 50 50 Hot Springs AR 96 79 95 77 / 20 20 20 30 Little Rock AR 96 78 96 78 / 20 20 20 30 Monticello AR 96 78 96 79 / 20 20 10 20 Mount Ida AR 95 78 93 75 / 20 20 20 30 Mountain Home AR 95 76 91 73 / 60 30 50 50 Newport AR 95 78 95 76 / 40 30 40 30 Pine Bluff AR 96 77 94 78 / 20 20 20 20 Russellville AR 98 77 94 76 / 30 20 20 40 Searcy AR 96 77 95 76 / 30 20 20 30 Stuttgart AR 96 77 95 78 / 20 20 20 20 && .LZK Watches/Warnings/Advisories... Heat Advisory until 8 PM CDT this evening FOR Arkansas-Bradley- Calhoun-Clark-Cleburne-Cleveland-Conway-Dallas-Desha-Drew- Faulkner-Garland-Grant-Hot Spring-Independence-Jackson-Jefferson- Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery-Ouachita-Perry- Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White- Woodruff-Yell. && $$ Short Term...59 / Long Term...66
Area Forecast Discussion...Updated for Aviation National Weather Service Little Rock AR 1215 PM CDT THU JUL 7 2016 .AVIATION... Overall VFR flight conditions are expected. Patchy MVFR may be seen especially associated with showers or isolated thunderstorms. Winds are expected to be southeast to southwest at 10 to 20 mph with some gusts to around 25 mph in spots. After sunset, winds will lower to 5 to 15 mph. Tonight, isolated convection may be seen over northern Arkansas and affect KHRO and KBPK Tafs. Winds will lower to mainly below 10 mph. (59) && .Prev Discussion.../ Issued 1000 AM CDT THU JUL 7 2016 Earlier update to add scattered convection over northern AR. Complex over MO has helped develop this convection associated with short wave energy moving through the northwest upper flow. Breezy south to southwest winds of 10 to 20 with gusts to 25 mph across AR. Will monitor for possible lake wind advisory. Otherwise, temperatures will warm to the 90s today, and with the added humidity, heat index values will reach around 105 degrees. A heat advisory is in effect for most of AR except the northern areas. Late morning update will fine tune convection chances, possibly adding a bit more southern areas in slight chance area. (59) && .PREV DISCUSSION...(ISSUED 358 AM CDT THU JUL 7 2016 SHORT TERM...Today Through Friday Night Similar setup to yesterday across the region with surface high pressure in place to the southeast and low pressure noted across the Southern Plains. Two MCS`s noted across the region with the first impacting Tennessee/Kentucky and the second moving out of SE Nebraska into northeastern Kansas. Should see fewer impacts to the forecast area from upstream MCS in Kansas due to more northerly location and easterly trajectory. Early morning HRRR runs attempt to initiate some shower and thunderstorm activity across E Oklahoma with a weak shortwave in the mean flow and shift this activity toward Arkansas throughout the day. No activity has manifested itself as of 09z so will keep forecast dry attm though wouldn`t be surprised to see at least a few isolated showers develop. SW flow at the surface will be in place again today and winds will be enhanced due to increased pressure gradient. Wind speeds will likely be aoa 12-18mph with gusts as high as 25mph at times. The other notable mention of the day goes to heat index values across the state. With dewpoints in the 70s and temps cranking into the mid to upper 90s, another run at heat index values of 105 will be made this afternoon. Rain chances will be in place across mainly northern Arkansas on Friday as a surface boundary approaches from the NW. Additionally, the H500 pattern begins to show signs of transitioning to more of an active period with more of a NW flow expected. Will have to keep an eye on temps/heat indices Friday as heat indices could approach heat advisory levels once again across the southern half of the state. Could see chances for a more notable thunderstorm complex approaching the state from the northwest late Friday night. LONG TERM...Saturday Through Wednesday As a ridge of high pressure weakens over the southeast United States, a cold front will be allowed to drop through the Ohio and Tennessee Valleys during the upcoming weekend. The front may actually make it into northeast Arkansas. Isolated to scattered showers and thunderstorms are in the forecast. Given more clouds, it will be slightly cooler. A few storms may be severe as the front nears the region. Damaging winds and hail will be the main concerns. An organized severe weather event is not expected at this point. Heavy downpours in the northeast half of the state may result in localized flash flooding. Heading into early next week, a big trough of low pressure will be noted out west. This will cause ridging farther east, and the front will be forced to move away from Arkansas to the north. The heat will return, and precipitation chances will decrease. Temperatures will be near to a little above average for much of the period. Readings may be a touch below average toward the Missouri border this weekend near the aforementioned front. && .LZK Watches/Warnings/Advisories... Heat Advisory from 10 AM this morning to 8 PM CDT this evening FOR Arkansas-Bradley-Calhoun-Clark-Cleburne-Cleveland-Conway- Dallas-Desha-Drew-Faulkner-Garland-Grant-Hot Spring-Independence- Jackson-Jefferson-Johnson-Lincoln-Logan-Lonoke-Monroe-Montgomery- Ouachita-Perry-Pike-Polk-Pope-Prairie-Pulaski-Saline-Scott-Van Buren-White-Woodruff-Yell. && $$ Aviation...226
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
613 AM CDT SAT JUL 9 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 322 AM CDT SAT JUL 9 2016 A broad upper level ridge will move east across the central and southern plains Today and Tonight. Early this morning an area of elevated thunderstorms were developing across southeast NE due to weak isentropic lift. These storms were back building to the northwest but were slowly shifting southeast. The north central and northeast counties may see an isolated thunderstorm during the morning hours. Today and Tonight, most numerical models show any weak outflow boundaries washing out through the day. The WRF, HRRR and RAP models show the potential for a few elevated thunderstorms this morning across the CWA but these should diminish as the boundary layer mixes deeper. The WRF solutions along with the HRRR forecast isolated thunderstorms to develop across portions of east central and early this evening across portions of northeast and east central KS ahead of minor MCV that develops across northeast NE this morning and tracks southeast. There is a very weak cap so any type of minor ascent could cause a few isolated storms to develop during the late afternoon and into the early evening hours. The remainder of the night will remain dry. Highs Today will reach the upper 80s to mid 90s. Surface dewpoints will remain in the lower to mid 70s through the afternoon hours which will cause heat indices to rise into the mid 90s to around 100 degrees. .LONG TERM...(Sunday through Friday) Issued at 322 AM CDT SAT JUL 9 2016 Sunday afternoon and much of Monday should remain dry with a mid to upper ridge advecting overhead. Should mix to around the 800mb level on both days which should help our temps to rise into the mid 90s. With ample sunshine and dewpoints in the upper 60s and low 70s, heat index values will be hot but should remain under advisory level criteria. Winds will likely increase ahead of the deepening North Pac Low as it advects into the Northern Plains region. This system leaves questions about what type of weather we see late Monday evening into Tuesday morning and how much. ECMWF and GFS are coming into good agreement on positioning of major features, but the NAM is slowing the arrival of the cold boundary perhaps lifting the overall system to a more northerly track quicker. Regardless, at this time, it is hard to say with great certainty on what specific type of storms will occur and coverage. Better large scale ascent is focused to the north of the CWA. Overall hint is that the cold push is modified and slows down as it enters the Central Plains. This system eventually sets up a stationary boundary across the region that allows for precip chances off and on the bulk of the week ahead. But for Monday night into Tuesday, storms may have a hard time getting going initially as the 700mb level temps seem to be at or above 12C. Additionally, if the cold push is weak, then with weak forcing, it may be too hard to get storms to form this far south until later into the night as a LLJ noses into the area. Perhaps storms become are more elevated and form a complex that then propagates east with time. Then into the day on Tuesday better shear profiles seem to take shape for the rest of the period. With a transition in the upper levels to a quasi-zonal to northwesterly flow regime, there could be periods where storm chances are greater through at least Thursday, but hard to pinpoint at this time with any shortwave advecting overhead. Bottom line, some storms could be strong to severe given a conditionally unstable environment in place. High temps remain in the 90s with no strong advection either way in place for any prolonged period of time. && .AVIATION...(For the 12Z TAFS through 12Z Sunday Morning) Issued at 612 AM CDT SAT JUL 9 2016 VFR conditions are expected through the period. Winds from the southeast will generally be under 10 kts. The chances for any TSRA are too low to mention at a given terminal at this time. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...Drake AVIATION...Heller Area Forecast Discussion National Weather Service Tucson AZ 325 PM MST SAT JUL 9 2016 .SYNOPSIS...Dry conditions will prevail this weekend and next week. As this occurs, temperatures will remain several degrees above average for most of next week. && .DISCUSSION...A few showers and thunderstorms managed to develop this afternoon near the International border. Otherwise...skies were clear to partly cloudy across southeast Arizona. A drier westerly flow developing in response to a system passing through the northern tier states will keep deeper moisture south and east of the region. Without this moisture in place, shower and thunderstorm activity will remain very limited through next week. The drier air will also help keep afternoon temperatures several degrees above normal. && .AVIATION...VALID THRU 11/00Z. VFR conditions through the period for most of the area with isolated -SHRA/-TSRA continuing thru about 10/03Z, mainly across the White Mountains NE of KSAD and along the Int`l border from KOLS to KDUG. Surface winds will remain wly/nwly at about 10-15 kts with some stronger winds in the Gila River Valley near KSAD. Light and terrain driven winds will then resume during the overnight hours, then becoming wly/nwly winds midday Sunday. Dry conditions are expected area wide Sunday. && .FIRE WEATHER...A few showers or thunderstorms will continue into early this evening, mainly across the White Mountains and along the International border from Nogales to Douglas. Dry conditions will then prevail through Thursday, with only a slight chance of storms near the international border on Friday. 20-ft westerly winds may approach 20 mph Sunday and Monday afternoons near the NM and International border areas. Otherwise, wind will generally follow terrain at 15 mph or less. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Tucson AZ 325 PM MST SAT JUL 9 2016 .SYNOPSIS...Dry conditions will prevail this weekend and next week. As this occurs, temperatures will remain several degrees above average for most of next week. && .DISCUSSION...A few showers and thunderstorms managed to develop this afternoon near the International border. Otherwise...skies were clear to partly cloudy across southeast Arizona. A drier westerly flow developing in response to a system passing through the northern tier states will keep deeper moisture south and east of the region. Without this moisture in place, shower and thunderstorm activity will remain very limited through next week. The drier air will also help keep afternoon temperatures several degrees above normal. && .AVIATION...VALID THRU 11/00Z. VFR conditions through the period for most of the area with isolated -SHRA/-TSRA continuing thru about 10/03Z, mainly across the White Mountains NE of KSAD and along the Int`l border from KOLS to KDUG. Surface winds will remain wly/nwly at about 10-15 kts with some stronger winds in the Gila River Valley near KSAD. Light and terrain driven winds will then resume during the overnight hours, then becoming wly/nwly winds midday Sunday. Dry conditions are expected area wide Sunday. && .FIRE WEATHER...A few showers or thunderstorms will continue into early this evening, mainly across the White Mountains and along the International border from Nogales to Douglas. Dry conditions will then prevail through Thursday, with only a slight chance of storms near the international border on Friday. 20-ft westerly winds may approach 20 mph Sunday and Monday afternoons near the NM and International border areas. Otherwise, wind will generally follow terrain at 15 mph or less. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
  [top] Area Forecast Discussion National Weather Service Flagstaff AZ 255 PM MST SAT JUL 9 2016 .SYNOPSIS...A dry southwest flow regime will remain over northern Arizona through Friday with fair and breezy weather on the way. A passing weather disturbance will bring stronger winds from Sunday into Monday producing a heightened fire weather threat. && .DISCUSSION...Models insist that high pressure aloft will persist across Texas and northern Mexico into next weekend. At the same time, models show a series of low pressure systems moving across the Pacific Northwest. Look for this pattern to bring near normal daytime temperatures, breezy daytime winds and dry weather to northern Arizona over the coming week. The only concern is a heightened fire weather threat from Sunday into Monday due to stronger winds. The strongest in the series of Pacific Northwest low pressure system will brush Arizona on Sunday. The resultant stronger pressure gradient will produce southwest winds of 15 to 25 mph gusting to 30 to 40 mph from the Mogollon Rim northward. A Red Flag Warning is in effect for Sunday. Behind the low on Monday, northern Arizona will still see southwest winds in the 10 to 20 mph range with gusts to over 30 mph so fire danger will still be a concern. && .AVIATION...For the 00Z package...Expect VFR conditions under mostly clear skies for the 24 hour forecast period. Gusty southwest winds will persist into this evening and develop again Sunday afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A trough moving through the northern Great Basin this weekend will bring windy and dry conditions to the area into early next week. The windiest day will be Sunday, and a Red Flag Warning has been issued for the northern portions of the district. Tuesday through Thursday...Dry weather will continue with less wind and near average temperatures. && .FGZ WATCHES/WARNINGS/ADVISORIES...Red Flag Warning from 11 AM to 8 PM MST Sunday FOR AZZ104>107-109>114-139-140. && $$ PUBLIC...McCollum AVIATION...KD FIRE WESTERH...KD For Northern Arizona weather information visit weather.gov/flagstaff
  [top] Area Forecast Discussion National Weather Service Phoenix AZ 158 PM MST SAT JUL 9 2016 .UPDATE...To Aviation Discussion... && .SYNOPSIS... A dry and stable airmass will remain across much of the desert southwest through next week, giving the region a significant break in the monsoon. Afternoon temperatures on the lower deserts will remain near, or a few degrees above normal through the entire period. && .DISCUSSION... Tonight through Saturday... Our extended break in the monsoon is still in the forecast through at least the end of the upcoming workweek. All of the global model suites and virtually all of their respective ensemble members continue to move a very deep upper trof (for July) eastward across the Northern Rockies on Sunday and Monday, then keep that same region under overall long-wave trofing through the rest of next week. To the south of this upper trof, unseasonably strong westerly are expected to prevail over all the desert southwest through the entire period. These westerlies will keep monsoon moisture well off to our south along the International Border and points south. Thus, convective activity/chances for measurable rain will be virtually non-existent through at least Friday. There continues to be some indication on the GFS model output that moisture will begin to spread back northward into SE AZ next Saturday as the westerlies begin to retreat northward, with an increase in moisture levels possible over our CWA by next Sunday. Model guidance is keeping our high temperatures in a tight range through the entire period, with lower desert highs remaining mainly in the 107-112 degree range. Although overnight lows are expected to remain mostly in the mid 70-mid 80 range through all of next week, lower dewpoints (in the 30s) will likely make it feel a bit cooler during the middle part of next week. && .AVIATION... South-Central Arizona including KPHX, KIWA and KSDL: Clear skies and erratic winds to continue for the afternoon (especially for KPHX), before settling into slightly elevated west directions during the evening and lingering into the overnight hours. Afternoon/early evening gustiness up to 20kts is possible. A weather system passing through the Great Basin to our north will allow for winds to take up their typical diurnal headings, with a more pronounced and sustained easterly drift into the Phoenix area terminals early tomorrow morning, possibly as early as 10/08z. Southeast California/Southwest Arizona including KIPL and KBLH: Weather system passing through the Great Basin to our north will spread even drier air into the SE CA deserts, allowing for generally clear skies and zero chances for any storm activity. Winds to favor S-SW headings for KBLH with another round of afternoon gustiness. Winds will turn westerly for KIPL with some elevated sundowner breezes lingering into the overnight hours. No aviation concerns at the TAF sites for at least the next 24 hours. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Tuesday through Saturday... An extended break in the Monsoon activity will continue into work week, with unseasonably strong westerly flow aloft and dewpoints generally below the typical Monsoonal values of 50 to 60 degrees. Conditions look to be at their driest Monday as a strong trough passes through the Great Basin to our north and spreads a drier airmass into the Southwest region. With temperatures hovering near a warm seasonal average, minimum afternoon humidity levels will fall to around 10% over lower elevations, and 15-20% in higher terrain. Overnight recovery will only be fair. Occasionally breezy southwest afternoon winds will affect the region, however speeds will remain well below any critical thresholds. Overall, weather conditions will mirror a typical early/mid June versus mid July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Percha AVIATION...Nolte FIRE WEATHER...Nolte/Kuhlman
Area Forecast Discussion National Weather Service Phoenix AZ 1235 PM MST SAT JUL 9 2016 && .SYNOPSIS... A dry and stable airmass will remain across much of the desert southwest through next week, giving the region a significant break in the monsoon. Afternoon temperatures on the lower deserts will remain near, or a few degrees above normal through the entire period. && .DISCUSSION... Tonight through Saturday... Our extended break in the monsoon is still in the forecast through at least the end of the upcoming workweek. All of the global model suites, and virtually all of their respective ensemble members continue to move a very deep upper trof (for July) eastward across the Northern Rockies on Sunday and Monday, then keep that same region under overall long-wave trofing through the rest of next week. To the south of this upper trof, unseasonably strong westerly are expected to prevail over all the desert southwest through the entire period. These westerlies will keep monsoon moisture well off to our south, along the International Border and points south. Thus, convective activity/chances for measurable rain will be virtually non-existent through at least Friday. There continues to be some indication on the GFS model output that moisture will begin to spread back northward into SE AZ next Saturday as the westerlies begin to retreat northward, with an increase in moisture levels possible over our cwa by next Sunday. Model guidance is keeping our high temperatures in a tight range through the entire period, with lower desert highs remaining mainly in the 107-112 degree range. Although overnight lows are expected to remain mostly in the mid 70- mid 80 range through all of next week, lower dewpoints (in the 30s) will likely make it feel a bit cooler during the middle part of next week. && .AVIATION... South-Central Arizona including KPHX, KIWA and KSDL: Skies to be generally clear next 24 hours at all sites; there is no threat of weather of any kind through the weekend including storms or gusty outflow winds. Otherwise winds will hold onto typical diurnal tendencies. Again, we may see some afternoon and early evening gustiness out of the west today but really there are no aviation concerns for the near future. Southeast California/Southwest Arizona including KIPL and KBLH: Dry weather expected across the lower deserts next 24 hours with skies to be clear. Winds should favor the south to southwest at KBLH next 24 hours with some afternoon gustiness possible again today. Morning southeast winds at KIPL will shift around to the west during the early evening hours with a few gusts to 20kt possible. No aviation concerns at the TAF sites for at least the next 24 hours. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Monday through Friday... An extended break in the Monsoon activity will continue into work week, with unseasonably strong westerly flow aloft and dewpoints generally below the typical Monsoonal values of 50 to 60 degrees. Conditions look to be at their driest Monday as a strong trough passes through the Great Basin to our north and spreads a drier airmass into the Southwest region. With temperatures hovering near a warm seasonal average, minimum afternoon humidity levels will fall to around 10% over lower elevations, and 15-20% in higher terrain. Overnight recovery will only be fair. Occasionally breezy southwest afternoon winds will affect the region, however speeds will remain well below any critical thresholds. Overall, weather conditions will mirror a typical early/mid June versus mid July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Percha AVIATION...Kuhlman FIRE WEATHER...Nolte/Kuhlman
Area Forecast Discussion National Weather Service Tucson AZ 932 AM MST SAT JUL 9 2016 .SYNOPSIS...We should see a few thunderstorms again mainly south and southeast of Tucson this afternoon. Storms will become even fewer and farther between over the next several days as we see additional drying. As this occurs, temperatures will climb to several degrees above average for most of next week. && .DISCUSSION...A drier weather pattern will remain in place this weekend through the early one-half of next week. Still enough moisture in place today for a few mountain showers or thunderstorms well south and east of Tucson. That said, the current forecast looked on track with above normal day time temperatures on tap this weekend. Please refer to the additional sections in this product for more details. && .AVIATION...VALID THRU 10/18Z. VFR conditions and mostly clear skies this morning with isolated -SHRA/-TSRA developing this afternoon, mainly across the White Mtns NE of KSAD and along the Int`l border from KOLS to KDUG. SFC wind will generally be terrain driven at less than 10 kts this morning, becoming wly/nwly at 10-15 kts this afternoon. The strongest wind will prevail through the Gila Valley near KSAD. Light and terrain driven winds will then resume during the overnight hours. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A few showers or thunderstorms may occur this afternoon, mainly across the White Mountains and along the International border from Nogales to Douglas. Dry conditions will then prevail through next Friday. 20-ft westerly winds may approach 20 mph Sunday and Monday afternoons near the NM and International border areas. Otherwise, wind will generally follow terrain at 15 mph or less. && .PREV DISCUSSION...With weak flow and drier air fighting to keep the moisture away, we continue in a very low grade monsoon pattern today. Enough moisture for a few afternoon storms south and southeast of Tucson. As the broad troughiness enhances the westerly flow across the region, we will lose even that by Monday. At the southern periphery of trough influence, our heights and thicknesses will still be strong. Combined with the drying trend, our temperatures will run several degrees above average for much of the coming week. The unseasonable pattern will even lower moisture levels across northwest Mexico, with most organized convection retreating to southern Sonora and southwest Chihuahua early in the new week. We should see some moisture return the second half of next week, but a lot will depend on where we can consolidate a new high center. The GFS has some hopeful lower level surge signals late next week, while the ECMWF restarts the monsoon with a favorable high position early the following week. These scenarios are not mutually exclusive and both increase our chances of one or more mechanisms bringing the deeper moisture back. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Tucson AZ 932 AM MST SAT JUL 9 2016 .SYNOPSIS...We should see a few thunderstorms again mainly south and southeast of Tucson this afternoon. Storms will become even fewer and farther between over the next several days as we see additional drying. As this occurs, temperatures will climb to several degrees above average for most of next week. && .DISCUSSION...A drier weather pattern will remain in place this weekend through the early one-half of next week. Still enough moisture in place today for a few mountain showers or thunderstorms well south and east of Tucson. That said, the current forecast looked on track with above normal day time temperatures on tap this weekend. Please refer to the additional sections in this product for more details. && .AVIATION...VALID THRU 10/18Z. VFR conditions and mostly clear skies this morning with isolated -SHRA/-TSRA developing this afternoon, mainly across the White Mtns NE of KSAD and along the Int`l border from KOLS to KDUG. SFC wind will generally be terrain driven at less than 10 kts this morning, becoming wly/nwly at 10-15 kts this afternoon. The strongest wind will prevail through the Gila Valley near KSAD. Light and terrain driven winds will then resume during the overnight hours. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A few showers or thunderstorms may occur this afternoon, mainly across the White Mountains and along the International border from Nogales to Douglas. Dry conditions will then prevail through next Friday. 20-ft westerly winds may approach 20 mph Sunday and Monday afternoons near the NM and International border areas. Otherwise, wind will generally follow terrain at 15 mph or less. && .PREV DISCUSSION...With weak flow and drier air fighting to keep the moisture away, we continue in a very low grade monsoon pattern today. Enough moisture for a few afternoon storms south and southeast of Tucson. As the broad troughiness enhances the westerly flow across the region, we will lose even that by Monday. At the southern periphery of trough influence, our heights and thicknesses will still be strong. Combined with the drying trend, our temperatures will run several degrees above average for much of the coming week. The unseasonable pattern will even lower moisture levels across northwest Mexico, with most organized convection retreating to southern Sonora and southwest Chihuahua early in the new week. We should see some moisture return the second half of next week, but a lot will depend on where we can consolidate a new high center. The GFS has some hopeful lower level surge signals late next week, while the ECMWF restarts the monsoon with a favorable high position early the following week. These scenarios are not mutually exclusive and both increase our chances of one or more mechanisms bringing the deeper moisture back. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Flagstaff AZ 921 AM MST SAT JUL 9 2016 .SYNOPSIS...A dry southwest flow regime will remain over northern Arizona through Friday with fair and breezy weather on the way. A passing weather disturbance will bring stronger winds from Sunday into Monday producing a heightened fire weather threat. && .DISCUSSION...Models promise that low pressure will remain centered over the Pacific Northwest with high pressure stretching across Texas/northern Mexico into next weekend. This pattern will continue to bring near normal daytime temperatures, breezy daytime winds and dry weather. The only real concern weather wise is a heightened fire weather threat on Sunday and Monday. A shortwave trough will brush Arizona bringing southwest winds of 15 to 25 mph gusting to 30 to 40 mph from the Mogollon Rim northward each day. The strongest of these winds will be on Sunday where a Fire Weather Watch is in effect. Looking to the future...A few model runs hinting at the return of the monsoon by late next weekend but others continue the dry weather. Keep your fingers crossed. && .AVIATION...For the 12Z package...Expect VFR conditions and clear skies for the 24 hour forecast period. SW sfc winds 15-25kts most areas from 18z-01z today. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A trough moving through the northern Great Basin this weekend will bring windy and dry conditions to the area. The windiest day will be Sunday, a Fire Weather Watch has been issued for the northern portions of the district. Monday through Wednesday...Dry weather will continue with less wind and near average temperatures. && .FGZ WATCHES/WARNINGS/ADVISORIES...Fire Weather Watch from Sunday morning through Sunday evening FOR AZZ104>107-109>114-139-140. && $$ PUBLIC...McCollum/Bohlin AVIATION...KD/Peterson FIRE WEATHER...Peterson For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Phoenix AZ 830 AM MST SAT JUL 9 2016 && .SYNOPSIS... A dry and stable airmass will remain across much of the desert southwest through next week, giving the region a significant break in the monsoon. Afternoon temperatures on the lower deserts will remain near, or a few degrees above normal through next week. && .DISCUSSION... Another very quiet morning across our cwa as light westerly flow through the column continues to keep monsoon moisture well off to our south and east. Very warm temperatures in the mid-levels of the atmosphere (500mb temp -5.7C on the 12z KPSR sounding) and lingering low-level moisture (sfc dewpoints near 50 degrees) helped to keep overnight lows up a bit across south-central AZ this morning, with Phoenix Sky Harbor reporting a low of 87. A dry forecast is still on tap for today with highs across the lower deserts still forecast to end up in the 108-112 degree range. Based on current trends, inherited forecasts are still looking good, and no updates are planned at this time. && .PREVIOUS DISCUSSION... Today through Saturday... Weather balloon soundings Friday evening continued to detect remnant monsoon moisture over parts of southeast AZ, with continued moisture seeps from Mexico into that area this weekend. This moisture would be enough for more mountain thunderstorms if it weren`t for an atypically warm mid level atmosphere. Typical 500 mb temps for July and August run about minus 6-7 degrees C. For our forecast area, southeast CA to south central AZ, it will remain hot and dry this weekend. For next week, low level westerly winds kick in a little stronger with more airmass drying expected. In fact surface dewpoints over our southwest and south central AZ desert zones, including Phoenix will likely fall into the upper 20s and lower 30s. Extended range models forecast monsoon moisture to push north again into southern AZ from Mexico next Saturday, but that`s still a long way off. Otherwise mostly clear skies with slightly above normal afternoon temperatures are forecast next week. && .AVIATION... South-Central Arizona including KPHX, KIWA and KSDL: Skies to be generally clear next 24 hours at all sites; there is no threat of weather of any kind through the weekend including storms or gusty outflow winds. Otherwise winds will hold onto typical diurnal tendencies. Again, we may see some afternoon and early evening gustiness out of the west today but really there are no aviation concerns for the near future. Southeast California/Southwest Arizona including KIPL and KBLH: Dry weather expected across the lower deserts next 24 hours with skies to be clear. Winds should favor the south to southwest at KBLH next 24 hours with some afternoon gustiness possible again today. Morning southeast winds at KIPL will shift around to the west during the early evening hours with a few gusts to 20kt possible. No aviation concerns at the TAF sites for at least the next 24 hours. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Monday through Friday... An extended break in the Monsoon activity will continue into work week, with unseasonably strong westerly flow aloft and dewpoints generally below the typical Monsoonal values of 50 to 60 degrees. Conditions look to be at their driest Monday as a strong trough passes through the Great Basin to our north and spreads a drier airmass into the Southwest region. With temperatures hovering near a warm seasonal average, minimum afternoon humidity levels will fall to around 10% over lower elevations, and 15-20% in higher terrain. Overnight recovery will only be fair. Occasionally breezy southwest afternoon winds will affect the region, however speeds will remain well below any critical thresholds. Overall, weather conditions will mirror a typical early/mid June versus mid July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Percha/Vasquez AVIATION...Kuhlman FIRE WEATHER...Nolte/Kuhlman
Area Forecast Discussion National Weather Service Phoenix AZ 435 AM MST SAT JUL 9 2016 .UPDATE...Updated aviation discussion... && .SYNOPSIS... A dry and stable airmass will remain across much of the desert southwest through next week, giving the region a significant break in the monsoon. Afternoon temperatures on the lower deserts will remain near, or a few degrees above normal through next week. && .DISCUSSION... Today through Saturday... Weather balloon soundings Friday evening continued to detect remnant monsoon moisture over parts of southeast AZ, with continued moisture seeps from Mexico into that area this weekend. This moisture would be enough for more mountain thunderstorms if it weren`t for an atypically warm mid level atmosphere. Typical 500 mb temps for July and August run about minus 6-7 degrees C. For our forecast area, southeast CA to south central AZ, it will remain hot and dry this weekend. For next week, low level westerly winds kick in a little stronger with more airmass drying expected. In fact surface dewpoints over our southwest and south central AZ desert zones, including Phoenix will likely fall into the upper 20s and lower 30s. Extended range models forecast monsoon moisture to push north again into southern AZ from Mexico next Saturday, but that`s still a long way off. Otherwise mostly clear skies with slightly above normal afternoon temperatures are forecast next week. && .AVIATION... South-Central Arizona including KPHX, KIWA and KSDL: Skies to be generally clear next 24 hours at all sites; there is no threat of weather of any kind through the weekend including storms or gusty outflow winds. Otherwise winds will hold onto typical diurnal tendencies. Again, we may see some afternoon and early evening gustiness out of the west today but really there are no aviation concerns for the near future. Southeast California/Southwest Arizona including KIPL and KBLH: Dry weather expected across the lower deserts next 24 hours with skies to be clear. Winds should favor the south to southwest at KBLH next 24 hours with some afternoon gustiness possible again today. Morning southeast winds at KIPL will shift around to the west during the early evening hours with a few gusts to 20kt possible. No aviation concerns at the TAF sites for at least the next 24 hours. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Monday through Friday... An extended break in the Monsoon activity will continue into work week, with unseasonably strong westerly flow aloft and dewpoints generally below the typical Monsoonal values of 50 to 60 degrees. Conditions look to be at their driest Monday as a strong trough passes through the Great Basin to our north and spreads a drier airmass into the Southwest region. With temperatures hovering near a warm seasonal average, minimum afternoon humidity levels will fall to around 10% over lower elevations, and 15-20% in higher terrain. Overnight recovery will only be fair. Occasionally breezy southwest afternoon winds will affect the region, however speeds will remain well below any critical thresholds. Overall, weather conditions will mirror a typical early/mid June versus mid July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Vasquez AVIATION...Kuhlman FIRE WEATHER...Nolte/Kuhlman
Area Forecast Discussion National Weather Service Flagstaff AZ 417 AM MST SAT JUL 9 2016 .SYNOPSIS...A low pressure system along the west coast and the high pressure ridge south of Arizona will keep us in a dry southwesterly flow regime through next Friday. A trough moving through the western states will bring stronger winds on Sunday with good chances for critical fire weather conditions. In the longer term outlook there`s continued early signs the high pressure ridge to our south may migrate northward possibly opening up the door to Monsoon moisture by the third week in July. && .DISCUSSION...A long wave trough remains anchored along the west coast with the subtropical ridge south of Arizona. This pattern brings dry air into the state lasting through next week Friday. We continue to have high confidence in this extended dry break in the Monsoon weather pattern. On Sunday, a short wave trough will move through the western states increasing afternoon wind speeds likely exceeding our critical fire weather thresholds for most areas north of the interstate 40 corridor. A Fire Weather Watch has been issued for this time period. Looking into the extended outlook, the American GFS weather model continues to show early positive signs that the subtropical ridge to our south will migrate northward to a position more favorable for Monsoon moisture advection. This potential pattern shift to wetter weather may develop in the third week of July. Our confidence this far out however is only fair and precise timing of the additional moisture into northern Arizona will have to wait until the timer period gets closer. && .AVIATION...For the 12Z package...Expect VFR conditions and clear skies for the 24 hour forecast period. SW sfc winds 15-25kts most areas from 18z-01z today. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A trough moving through the northern Great Basin this weekend will bring windy and dry conditions to the area. The windiest day will be Sunday, a Fire Weather Watch has been issued for the northern portions of the district. Monday through Wednesday...Dry weather will continue with less wind and near average temperatures. && .FGZ WATCHES/WARNINGS/ADVISORIES...Fire Weather Watch from Sunday morning through Sunday evening FOR AZZ104>107-109>114-139-140. && $$ PUBLIC...Bohlin AVIATION...Peterson FIRE WEATHER...Peterson For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Flagstaff AZ 417 AM MST SAT JUL 9 2016 .SYNOPSIS...A low pressure system along the west coast and the high pressure ridge south of Arizona will keep us in a dry southwesterly flow regime through next Friday. A trough moving through the western states will bring stronger winds on Sunday with good chances for critical fire weather conditions. In the longer term outlook there`s continued early signs the high pressure ridge to our south may migrate northward possibly opening up the door to Monsoon moisture by the third week in July. && .DISCUSSION...A long wave trough remains anchored along the west coast with the subtropical ridge south of Arizona. This pattern brings dry air into the state lasting through next week Friday. We continue to have high confidence in this extended dry break in the Monsoon weather pattern. On Sunday, a short wave trough will move through the western states increasing afternoon wind speeds likely exceeding our critical fire weather thresholds for most areas north of the interstate 40 corridor. A Fire Weather Watch has been issued for this time period. Looking into the extended outlook, the American GFS weather model continues to show early positive signs that the subtropical ridge to our south will migrate northward to a position more favorable for Monsoon moisture advection. This potential pattern shift to wetter weather may develop in the third week of July. Our confidence this far out however is only fair and precise timing of the additional moisture into northern Arizona will have to wait until the timer period gets closer. && .AVIATION...For the 12Z package...Expect VFR conditions and clear skies for the 24 hour forecast period. SW sfc winds 15-25kts most areas from 18z-01z today. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A trough moving through the northern Great Basin this weekend will bring windy and dry conditions to the area. The windiest day will be Sunday, a Fire Weather Watch has been issued for the northern portions of the district. Monday through Wednesday...Dry weather will continue with less wind and near average temperatures. && .FGZ WATCHES/WARNINGS/ADVISORIES...Fire Weather Watch from Sunday morning through Sunday evening FOR AZZ104>107-109>114-139-140. && $$ PUBLIC...Bohlin AVIATION...Peterson FIRE WEATHER...Peterson For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Tucson AZ 301 AM MST SAT JUL 9 2016 .SYNOPSIS...We should see a few thunderstorms again mainly south and southeast of Tucson this afternoon. Storms will become even fewer and farther between over the next several days as we see additional drying. As this occurs, temperatures will climb to several degrees above average for most of next week. && .DISCUSSION...With weak flow and drier air fighting to keep the moisture away, we continue in a very low grade monsoon pattern today. Enough moisture for a few afternoon storms south and southeast of Tucson. As the broad troughiness enhances the westerly flow across the region, we will lose even that by Monday. At the southern periphery of trough influence, our heights and thicknesses will still be strong. Combined with the drying trend, our temperatures will run several degrees above average for much of the coming week. The unseasonable pattern will even lower moisture levels across northwest Mexico, with most organized convection retreating to southern Sonora and southwest Chihuahua early in the new week. We should see some moisture return the second half of next week, but a lot will depend on where we can consolidate a new high center. The GFS has some hopeful lower level surge signals late next week, while the ECMWF restarts the monsoon with a favorable high position early the following week. These scenarios are not mutually exclusive and both increase our chances of one or more mechanisms bringing the deeper moisture back. && .AVIATION...VALID THRU 10/12Z. VFR conditions and mostly clear skies this morning with isolated -SHRA/-TSRA developing this afternoon, mainly across the White Mtns NE of KSAD and along the Int`l border from KOLS to KDUG. SFC wind will generally be terrain driven at less than 10 kts this morning, becoming wly/nwly at 10-15 kts this afternoon. The strongest wind will prevail through the Gila Valley near KSAD. Light and terrain driven winds will then resume during the overnight hours. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A few showers or thunderstorms may occur this afternoon, mainly across the White Mountains and along the International border from Nogales to Douglas. Dry conditions will then prevail through next Friday. 20-ft westerly winds may approach 20 mph Sunday and Monday afternoons near the NM and International border areas. Otherwise, wind will generally follow terrain at 15 mph or less. && .TWC WATCHES/WARNINGS/ADVISORIES... None. && $$ Meyer/French Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Phoenix AZ 256 AM MST SAT JUL 9 2016 .SYNOPSIS... A dry and stable airmass will remain across much of the desert southwest through next week, giving the region a significant break in the monsoon. Afternoon temperatures on the lower deserts will remain near, or a few degrees above normal through next week. && .DISCUSSION... Today through Saturday... Weather balloon soundings Friday evening continued to detect remnant monsoon moisture over parts of southeast AZ, with continued moisture seeps from Mexico into that area this weekend. This moisture would be enough for more mountain thunderstorms if it weren`t for an atypically warm mid level atmosphere. Typical 500 mb temps for July and August run about minus 6-7 degrees C. For our forecast area, southeast CA to south central AZ, it will remain hot and dry this weekend. For next week, low level westerly winds kick in a little stronger with more airmass drying expected. In fact surface dewpoints over our southwest and south central AZ desert zones, including Phoenix will likely fall into the upper 20s and lower 30s. Extended range models forecast monsoon moisture to push north again into southern AZ from Mexico next Saturday, but that`s still a long way off. Otherwise mostly clear skies with slightly above normal afternoon temperatures are forecast next week. && .AVIATION... South-Central Arizona including KPHX, KIWA and KSDL: Not much change in the overall weather pattern expected over the next 24 hours...and likely for the next several days or more as dry southwest to west flow aloft will dominate the weather affecting the Phoenix area terminals. Skies to be genly clear next 24 hours at all sites; there is no threat of weather of any kind through the weekend including storms or gusty outflow winds. Otherwise winds will hold onto typical diurnal tendencies, although they may be a bit slow to turn back to the east/southeast after midnight. Again, we may see some afternoon and early evening gustiness out of the west on Saturday but really there are no aviation concerns for the near future. Southeast California/Southwest Arizona including KIPL and KBLH: Dry weather expected across the lower deserts next 24 hours with skies to be clear. Winds should favor the south to southwest at KBLH next 24 hours with some afternoon gustiness possible on Saturday. Evening west winds at KIPL likely will return to the southeast during the morning hours on Saturday, then returning again to the west during the early evening hours Saturday with a few gusts to 20kt possible. No aviation concerns at the TAF sites for at least the next 24 hours. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Monday through Friday... An extended break in the Monsoon activity will continue into work week, with unseasonably strong westerly flow aloft and dewpoints generally below the typical Monsoonal values of 50 to 60 degrees. Conditions look to be at their driest Monday as a strong trough passes through the Great Basin to our north and spreads a drier airmass into the Southwest region. With temperatures hovering near a warm seasonal average, minimum afternoon humidity levels will fall to around 10% over lower elevations, and 15-20% in higher terrain. Overnight recovery will only be fair. Occasionally breezy southwest afternoon winds will affect the region, however speeds will remain well below any critical thresholds. Overall, weather conditions will mirror a typical early/mid June versus mid July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...Vasquez AVIATION...CB FIRE WEATHER...Nolte/Kuhlman
Area Forecast Discussion National Weather Service Flagstaff AZ 1015 PM MST FRI JUL 8 2016 .SYNOPSIS...Over the coming week low pressure will remain anchored along the west coast of the United State while high pressure wobbles over Texas. The result will be a dry southwest flow and a continuation of the break in the monsoon across northern Arizona. Nothing on the forecast horizon in terms of the return of moisture, stay tuned. && .UPDATE... No significant changes to the forecast under dry quiet conditions. Temperatures are on track, with winds decreasing overnight. Gusty winds will develop again late saturday afternoon. && .PREV DISCUSSION /245 PM MST/...The forecast models still show the pattern of high pressure over Texas/northern Mexico and low pressure across the Pacific Northwest hanging tough well into next week. Overall look for breezy afternoons, warm days and dry conditions across northern Arizona. Some moisture will linger over the White Mountains on Saturday for a slight chance of thunderstorms. The only real concern over the next seven days is an elevated fire weather threat on Sunday for northern Arizona. Warm and dry conditions will remain. In addition, a fast moving weather disturbance and associated strengthening pressure gradient will move through the western states. For northern Arizona this will mean sustained west to southwest winds in the 15 to 25 mph range with gusts to 35 mph. As a result, a Fire Weather Watch has been issued for Sunday. && .AVIATION...For the 06Z package...VFR conditions will continue over the next 24 hours. Expect gusty southwest winds saturday morning and afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect dry conditions and gusty southwest winds each afternoon this weekend. Isolated high-based thunderstorms are possible in the White Mountains Saturday. Critical fire weather conditions are forecast for some of our northern zones Sunday, and a Fire Weather Watch has been issued. Monday through Wednesday...Near average temperatures and dry conditions are forecast through the period. && .FGZ WATCHES/WARNINGS/ADVISORIES...Fire Weather Watch from Sunday morning through Sunday evening FOR AZZ104>107-109>114-139-140. && $$ PUBLIC...AT AVIATION...AT FIRE WEATHER...AT For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Flagstaff AZ 1015 PM MST FRI JUL 8 2016 .SYNOPSIS...Over the coming week low pressure will remain anchored along the west coast of the United State while high pressure wobbles over Texas. The result will be a dry southwest flow and a continuation of the break in the monsoon across northern Arizona. Nothing on the forecast horizon in terms of the return of moisture, stay tuned. && .UPDATE... No significant changes to the forecast under dry quiet conditions. Temperatures are on track, with winds decreasing overnight. Gusty winds will develop again late saturday afternoon. && .PREV DISCUSSION /245 PM MST/...The forecast models still show the pattern of high pressure over Texas/northern Mexico and low pressure across the Pacific Northwest hanging tough well into next week. Overall look for breezy afternoons, warm days and dry conditions across northern Arizona. Some moisture will linger over the White Mountains on Saturday for a slight chance of thunderstorms. The only real concern over the next seven days is an elevated fire weather threat on Sunday for northern Arizona. Warm and dry conditions will remain. In addition, a fast moving weather disturbance and associated strengthening pressure gradient will move through the western states. For northern Arizona this will mean sustained west to southwest winds in the 15 to 25 mph range with gusts to 35 mph. As a result, a Fire Weather Watch has been issued for Sunday. && .AVIATION...For the 06Z package...VFR conditions will continue over the next 24 hours. Expect gusty southwest winds saturday morning and afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect dry conditions and gusty southwest winds each afternoon this weekend. Isolated high-based thunderstorms are possible in the White Mountains Saturday. Critical fire weather conditions are forecast for some of our northern zones Sunday, and a Fire Weather Watch has been issued. Monday through Wednesday...Near average temperatures and dry conditions are forecast through the period. && .FGZ WATCHES/WARNINGS/ADVISORIES...Fire Weather Watch from Sunday morning through Sunday evening FOR AZZ104>107-109>114-139-140. && $$ PUBLIC...AT AVIATION...AT FIRE WEATHER...AT For Northern Arizona weather information visit weather.gov/flagstaff
Area Forecast Discussion National Weather Service Tucson AZ 940 PM MST FRI JUL 8 2016 .SYNOPSIS...A few thunderstorms may occur across the White Mountains and far southeastern sections Saturday afternoon. Otherwise, dry conditions will prevail this weekend and next week with above average temperatures. && .DISCUSSION...Isolated thunderstorms this afternoon and early evening were mainly across Santa Cruz and Cochise counties. As of 930 pm activity had ended across the areas with debris cloud cover across eastern Pima, Santa Cruz and Cochise counties. PW values this evening still holding above 1" from Tucson south and southeast. Will run out a quick update for overnight trends. Lowering PW values on Saturday with upper high over SW New Mexico will limit any thunderstorm activity to along the International border from Nogales east and across the White mountains. Highs on Saturday similar or slightly warmer than today. Check previous discussion below for details on the remainder of the forecast package through next Friday. Definitely not monsoonal like. && .AVIATION...VALID THRU 10/00Z. Scattered debris cloud cover from KTUS S and SE will continue to slowly dissipate. VFR conditions will occur Saturday, except for a few -TSRA/-SHRA NE of KSAD and across the Chiricahua Mountains NE of KDUG. SFC wind Saturday afternoon wly/nwly at 10-15 kts with gusts to 20 kts. The strongest wind will be near KSAD. Surface wind will be variable in direction at less than 12 kts at other times. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A few thunderstorms may occur Saturday afternoon across the White Mountains northeast of Safford, and across the Chiricahua Mountains in eastern Cochise County. Dry conditions will then prevail Saturday night through next Friday. 20-foot winds Sunday and Monday may approach 20 mph in some locales. Otherwise, 20-foot winds will be terrain driven at less than 15 mph. && .PREV DISCUSSION...Increasing westerly flow aloft Sunday and Monday due to a fairly tight mid-level gradient will continue the drying process. This pattern should also translate into gusty generally westerly winds during the afternoon hours. However, wind speeds will remain below wind advisory criteria. The GFS/ECMWF/CMC were nearly identical Tuesday through Friday with depicting a sprawling high pressure ridge aloft to encompass the southwestern CONUS. Have noted that the GFS was more robust versus the ECMWF/CMC with the depiction of light liquid rain amounts to encroach upon far southeastern sections periodically Wednesday thru Friday. Given the progged synoptic pattern, have opted for the drier ECMWF/CMC solutions for this forecast package. Thus, expect dry conditions to continue across southeast Arizona during the middle and latter part of next week. Expect only very minor daily temp changes Saturday through next Friday, with high temps to generally be at least a few degs below normal through the period. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion National Weather Service Phoenix AZ 900 PM MST FRI JUL 8 2016 .SYNOPSIS... A dry and stable airmass will remain across much of the desert southwest through next week, giving the region a significant break in the monsoon, with little or no chance for rainfall. Afternoon temperatures on the lower deserts will remain near, or a few degrees above, normal through the period. && .DISCUSSION... Early this evening, deep southwest flow aloft was present over all but far southeast Arizona, as deep upper troffing pushed into the Pacific Northwest coast, shunting the main high center southeast of Arizona and setting up stronger west to southwest flow aloft into the desert southwest. This deep southwest flow was easily seen in the area raobs, most prominent in Flagstaff and to slightly lesser an extent in Phoenix. The west flow has continued to erode moisture over the central deserts, the PWAT in Phoenix this evening was down to just 0.73 inches and surface dewpoints over the central deserts at 8 pm were mostly in the middle 40s - mostly down 3-10 degrees from 24 hours ago. IR imagery at 8 pm showed clear skies area wide. One small disturbance rotating around the upper high to our southeast had pushed up into far southeast Arizona this evening, increasing PWAT at Tucson to almost 1.3 inches and could be seen in the TUS sounding as a layer of southeast winds near 500 mb. The overall deep west/southwest flow impinging on the rest of Arizona ahead of the Pacific northwest troffing will keep this feature well to our southeast and it should not affect our weather tonight. For the rest of the night we can expect generally clear skies and gradually decreasing west winds along with mild to warm overnight low temperatures. Forecasts look to be in good shape and no updates are planned. .PREVIOUS DISCUSSION... Tonight through Saturday... Increasing westerly flow ahead of a deep upper trof is expected to continue to scour out any remaining monsoon moisture over extreme SE and eastern AZ during this period. The latest HRRR model run keeps all convective activity confined to areas to the south and east of Tucson and over the white Mountains, well outside of our CWA this afternoon/evening, with even less activity on tap on Saturday. 500 mb heights in the 593-595 dm range, 500 mb temps in the -4C to -5C range, along with mostly clear skies will allow temperatures to rise a bit above normal again on Saturday, with lower desert highs mostly in the 108-112 degree range. Sunday through next Friday... Further drying is expected across the region during this period as a very deep, and cold upper low center (for July) moves across the Northern Rockies during the early part of next week, bringing a chance for some rare mid-summer snowfall to the higher elevations of MT/WY. To the south of this low center, a band of anomalously strong westerlies are expected to move across the Great Basin/northern AZ region Sun-Tue. 700mb winds are expected to reach 30 kts, or even greater across parts of northern AZ, which are in the 99% (or higher) climatological percentile for this time of year, according to the NAEFS percentile tables. The main impact from this belt of very strong winds will be to mix drier air down to the sfc across the region, with sfc dewpoints likely falling into the 30s, or even 20s across most of our CWA. The dry airmass, combined with a bit of cooling aloft, will likely allow many outlying lower desert locations to see lows in the 70s each night. These cooler temperatures, combined with the lower RH`s will result in the nights feeling noticeably more pleasant than what we typically see this time of year. Highs will be near or just a bit above normal, mostly in the 105-110 degree range across the lower deserts. PWATS across the region will also be well below normal, in the 0.50-0.75 inch range, which is 1-2 SD below normal. Needless to say, chances for rainfall/thunderstorms during this entire period will be basically at zero as our extended break in the monsoon continues. && .AVIATION... South-Central Arizona including KPHX, KIWA and KSDL: Not much change in the overall weather pattern expected over the next 24 hours...and likely for the next several days or more as dry southwest to west flow aloft will dominate the weather affecting the Phoenix area terminals. Skies to be genly clear next 24 hours at all sites; there is no threat of weather of any kind through the weekend including storms or gusty outflow winds. Otherwise winds will hold onto typical diurnal tendencies, although they may be a bit slow to turn back to the east/southeast after midnight. Again, we may see some afternoon and early evening gustiness out of the west on Saturday but really there are no aviation concerns for the near future. Southeast California/Southwest Arizona including KIPL and KBLH: Dry weather expected across the lower deserts next 24 hours with skies to be clear. Winds should favor the south to southwest at KBLH next 24 hours with some afternoon gustiness possible on Saturday. Evening west winds at KIPL likely will return to the southeast during the morning hours on Saturday, then returning again to the west during the early evening hours Saturday with a few gusts to 20kt possible. No aviation concerns at the TAF sites for at least the next 24 hours. Aviation discussion not updated for amended TAFs. && .FIRE WEATHER... Monday through Friday... An extended break in the Monsoon activity will continue into work week, with unseasonably strong westerly flow aloft and dewpoints generally below the typical Monsoonal values of 50 to 60 degrees. Conditions look to be at their driest Monday as a strong trough passes through the Great Basin to our north and spreads a drier airmass into the Southwest region. With temperatures hovering near a warm seasonal average, minimum afternoon humidity levels will fall to around 10% over lower elevations, and 15-20% in higher terrain. Overnight recovery will only be fair. Occasionally breezy southwest afternoon winds will affect the region, however speeds will remain well below any critical thresholds. Overall, weather conditions will mirror a typical early/mid June versus mid July. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ Visit us on Facebook...Twitter...and at weather.gov/phoenix DISCUSSION...CB PREVIOUS DISCUSSION...Percha AVIATION...CB FIRE WEATHER...Nolte/Kuhlman
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1221 PM CDT SAT JUL 9 2016 ...Update to aviation forecast discussion... .SHORT TERM...(Today and Tonight) Issued at 322 AM CDT SAT JUL 9 2016 A broad upper level ridge will move east across the central and southern plains Today and Tonight. Early this morning an area of elevated thunderstorms were developing across southeast NE due to weak isentropic lift. These storms were back building to the northwest but were slowly shifting southeast. The north central and northeast counties may see an isolated thunderstorm during the morning hours. Today and Tonight, most numerical models show any weak outflow boundaries washing out through the day. The WRF, HRRR and RAP models show the potential for a few elevated thunderstorms this morning across the CWA but these should diminish as the boundary layer mixes deeper. The WRF solutions along with the HRRR forecast isolated thunderstorms to develop across portions of east central and early this evening across portions of northeast and east central KS ahead of minor MCV that develops across northeast NE this morning and tracks southeast. There is a very weak cap so any type of minor ascent could cause a few isolated storms to develop during the late afternoon and into the early evening hours. The remainder of the night will remain dry. Highs Today will reach the upper 80s to mid 90s. Surface dewpoints will remain in the lower to mid 70s through the afternoon hours which will cause heat indices to rise into the mid 90s to around 100 degrees. .LONG TERM...(Sunday through Friday) Issued at 322 AM CDT SAT JUL 9 2016 Sunday afternoon and much of Monday should remain dry with a mid to upper ridge advecting overhead. Should mix to around the 800mb level on both days which should help our temps to rise into the mid 90s. With ample sunshine and dewpoints in the upper 60s and low 70s, heat index values will be hot but should remain under advisory level criteria. Winds will likely increase ahead of the deepening North Pac Low as it advects into the Northern Plains region. This system leaves questions about what type of weather we see late Monday evening into Tuesday morning and how much. ECMWF and GFS are coming into good agreement on positioning of major features, but the NAM is slowing the arrival of the cold boundary perhaps lifting the overall system to a more northerly track quicker. Regardless, at this time, it is hard to say with great certainty on what specific type of storms will occur and coverage. Better large scale ascent is focused to the north of the CWA. Overall hint is that the cold push is modified and slows down as it enters the Central Plains. This system eventually sets up a stationary boundary across the region that allows for precip chances off and on the bulk of the week ahead. But for Monday night into Tuesday, storms may have a hard time getting going initially as the 700mb level temps seem to be at or above 12C. Additionally, if the cold push is weak, then with weak forcing, it may be too hard to get storms to form this far south until later into the night as a LLJ noses into the area. Perhaps storms become are more elevated and form a complex that then propagates east with time. Then into the day on Tuesday better shear profiles seem to take shape for the rest of the period. With a transition in the upper levels to a quasi-zonal to northwesterly flow regime, there could be periods where storm chances are greater through at least Thursday, but hard to pinpoint at this time with any shortwave advecting overhead. Bottom line, some storms could be strong to severe given a conditionally unstable environment in place. High temps remain in the 90s with no strong advection either way in place for any prolonged period of time. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Issued at 1221 PM CDT SAT JUL 9 2016 VFR ceilings over the area should remain SCT to BKN. Winds from the southwest will be under 10kts through the period. Any chances for TSRA are too low to mention at this time. && .TOP Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Gargan LONG TERM...Drake AVIATION...Heller
AREA FORECAST DISCUSSION
National Weather Service New Orleans LA
334 PM CDT SAT JUL 9 2016 .Discussion... Current synopsis shows a broad upper level trough passing across the northeastern United States and extending southward to the Appalachian Mountains while ridge is in place over the mid section of the country. At the surface the Bermuda ridge is extending westward across the Gulf of Mexico which is keeping moisture and dewpoints high across the CWA. Intense surface heating and a slightly sufficient low/mid level moisture has resulted in scattered convection again this afternoon. These storms shouldn`t produce much more than brief heavy rainfall and wind gusts to 30 mph but lightning could be frequent at times. Storms will dissipate with loss of daytime heating, only to return again Sunday as the cycle repeats. There will be a difference Sunday into Monday however as a weak upper develops and tracks over the lower Mississippi Valley. This will further weaken subsidence over the region and subsequently increase sh/ts coverage. Have kept previous forecast pops in the 40 to 60% range for those days which is slightly above guidance. The upper trough will diminish late in the day Monday and weak high pressure will try to develop east of the region. This will keep moisture levels high and in combination with typical summertime heat, persistent daytime thunderstorms can be expected. Temperatures will not fluctuate much from day to day. MEFFER && .AVIATION... Lake, sea and river breezes along with outflow boundaries increased the chances of convection near KMSY, KHUM, KNEW, KASD and KGPT this afternoon. However, atmosphere is worked over and convection has decreased. As a result, the tempo group with TS ending around 22z is on track. Once again ceilings should clear out for much of the overnight hours into early Sunday morning. However...scattered cu field may develop over taf sites by 13z sunday preceding better coverage of convection after 17z sunday which may affect all of our taf sites. 18 && .MARINE... Surface pressure over northeast and north central gulf will maintain a southwest to south flow over the coastal waters through next week. Will continue to see the typical diurnal wind increase/decrease as nocturnal winds rise to 10 to 15 knots which will carry over into the morning hours and then drop down the rest of the day closer to 10 knots or slightly less. Nocturnal sh/ts will also develop during the late night and early morning hours through the next several days. 18 && .DECISION SUPPORT... DSS code: Green. Deployed: None. Activation: None. Activities: None. Decision Support Services (DSS) Code Legend Green = No weather impacts that require action. Blue = Long-fused watch, warning, or advisory in effect or high visibility event. Yellow = Heightened impacts with short-fused watch, warning or advisory issuances; radar support. Orange = High Impacts; Slight to Moderate risk severe; nearby tropical events; HazMat or other large episodes. Red = Full engagement for Moderate risk of severe and/or direct tropical threats; Events of National Significance. && .PRELIMINARY POINT TEMPS/POPS... MCB 74 91 73 92 / 20 50 20 40 BTR 76 93 75 92 / 20 50 20 50 ASD 76 91 76 93 / 20 50 20 40 MSY 80 91 79 90 / 20 50 20 40 GPT 76 90 77 90 / 20 50 20 30 PQL 76 91 75 93 / 30 40 30 30 && .LIX Watches/Warnings/Advisories... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion National Weather Service New Orleans LA 148 PM CDT SAT JUL 9 2016 .AVIATION... ...18z Taf Issuance... Lake, sea and river breezes along with outflow boundaries have increased the chances of convection near KMSY, KHUM, KNEW, KASD and KGPT this afternoon. As a result, added tempo group with TS through 22z in taf forecast. Once again ceilings should clear out for much of the overnight hours into early Sunday morning. However...scattered cu field may develop over taf sites by 13z sunday. && .LIX Watches/Warnings/Advisories... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion National Weather Service Shreveport LA 1218 PM CDT SAT JUL 9 2016 .AVIATION... Scattered -SHRA/-TSRA have been ongoing North of keld since earlier this morning, but development has shifted South to near the aforementioned terminal. This has resulted in the insertion of a TEMPO group for a few hours. A VCTS at ktxk will be maintained as activity could near that terminal as well. Otherwise, MVFR CIGS have been slow to scatter out but continues to do so. Conditions should improve to VFR within the next hour or so. Light South to Southwest and at times variable wind conditions are expected for this TAF cycle. Chances for fog appears to be low as BKN-OVC VFR decks developing overnight /can not rule out a few terminals experiencing MVFR CIGS/ will discourage adequate radiational cooling. A few computer models hint at -SHRA/-TSRA developing overnight particularly near keld and ktxk once again. Will therefore hold on to VCTS/VCSH. && .PREV DISCUSSION... /issued 1050 AM CDT SAT JUL 9 2016/ DISCUSSION... Localized cluster of convection has persisted over a good chunk of sw AR this morning. Although normally redevelopment would be expected on a hot summer day, seeing nothing on either observed 12z soundings nor on mos guidance or other data to support this convection continuing long at least more than isold coverage. Thus, will maintain low pops with chance coverage for sw AR and Se Ok and isold further south today. Temps should rise about 10 degrees with mid and a few upper 90s possible this aftn. Temps just outside convection in sw AR rising into mid and upper 80s at 10 am, leaving only a small data sparse area where rainfall may prevent temps from reaching well into 90s, but too small an area to update entire fcst attm. Will keep an eye on trends up that way but will not make any changes to fcst attm./VII/. PREV DISCUSSION... /issued 327 AM CDT SAT JUL 9 2016/ DISCUSSION... Convection over w TX/nrn AR this morning sending quite a bit of CI streaming in over the ArkLaTex. Upper ridge fcst to continue to break down today by disturbances in increasing nw flow aloft, which will aid additional convection and cloud cover for our region. This, along with lower afternoon relative humidities, will keep us out of trouble as far as a Heat Advisory is concerned. A few sites, particularly over n LA, may briefly see heat index values reach 105, but most sites will remain below. Models more aggressive with bringing a pronounced upper trof swd along the nern/ern periphery of the wwd retreating ridge into our region by later this afternoon and into Sunday. Consequently, have increased PoPs during this timeframe from previous fcst packages. Trof looks to slowly drift ewd through Monday, gradually tapering our rain chances back down to chicken 20s. Upper ridge looks to stay w of our region as the upper pattern remains somewhat unsettled through the work week. Additionally, the sea breeze appears to be making a comeback as well, which will keep PoPs in for our srn portions of the region. In other good news, temps look to hover near guidance in the mid 90s, and although arguably hot, not expecting to need advisories attm. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 77 95 78 96 / 20 30 10 10 MLU 77 92 76 94 / 20 40 20 20 DEQ 74 93 75 95 / 20 30 20 10 TXK 76 93 77 96 / 20 30 20 10 ELD 75 92 76 95 / 20 40 20 20 TYR 77 95 76 96 / 10 30 10 10 GGG 77 95 77 96 / 10 30 10 10 LFK 77 95 77 95 / 10 30 10 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 29/07/12
Area Forecast Discussion National Weather Service Shreveport LA 1218 PM CDT SAT JUL 9 2016 .AVIATION... Scattered -SHRA/-TSRA have been ongoing North of keld since earlier this morning, but development has shifted South to near the aforementioned terminal. This has resulted in the insertion of a TEMPO group for a few hours. A VCTS at ktxk will be maintained as activity could near that terminal as well. Otherwise, MVFR CIGS have been slow to scatter out but continues to do so. Conditions should improve to VFR within the next hour or so. Light South to Southwest and at times variable wind conditions are expected for this TAF cycle. Chances for fog appears to be low as BKN-OVC VFR decks developing overnight /can not rule out a few terminals experiencing MVFR CIGS/ will discourage adequate radiational cooling. A few computer models hint at -SHRA/-TSRA developing overnight particularly near keld and ktxk once again. Will therefore hold on to VCTS/VCSH. && .PREV DISCUSSION... /issued 1050 AM CDT SAT JUL 9 2016/ DISCUSSION... Localized cluster of convection has persisted over a good chunk of sw AR this morning. Although normally redevelopment would be expected on a hot summer day, seeing nothing on either observed 12z soundings nor on mos guidance or other data to support this convection continuing long at least more than isold coverage. Thus, will maintain low pops with chance coverage for sw AR and Se Ok and isold further south today. Temps should rise about 10 degrees with mid and a few upper 90s possible this aftn. Temps just outside convection in sw AR rising into mid and upper 80s at 10 am, leaving only a small data sparse area where rainfall may prevent temps from reaching well into 90s, but too small an area to update entire fcst attm. Will keep an eye on trends up that way but will not make any changes to fcst attm./VII/. PREV DISCUSSION... /issued 327 AM CDT SAT JUL 9 2016/ DISCUSSION... Convection over w TX/nrn AR this morning sending quite a bit of CI streaming in over the ArkLaTex. Upper ridge fcst to continue to break down today by disturbances in increasing nw flow aloft, which will aid additional convection and cloud cover for our region. This, along with lower afternoon relative humidities, will keep us out of trouble as far as a Heat Advisory is concerned. A few sites, particularly over n LA, may briefly see heat index values reach 105, but most sites will remain below. Models more aggressive with bringing a pronounced upper trof swd along the nern/ern periphery of the wwd retreating ridge into our region by later this afternoon and into Sunday. Consequently, have increased PoPs during this timeframe from previous fcst packages. Trof looks to slowly drift ewd through Monday, gradually tapering our rain chances back down to chicken 20s. Upper ridge looks to stay w of our region as the upper pattern remains somewhat unsettled through the work week. Additionally, the sea breeze appears to be making a comeback as well, which will keep PoPs in for our srn portions of the region. In other good news, temps look to hover near guidance in the mid 90s, and although arguably hot, not expecting to need advisories attm. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 77 95 78 96 / 20 30 10 10 MLU 77 92 76 94 / 20 40 20 20 DEQ 74 93 75 95 / 20 30 20 10 TXK 76 93 77 96 / 20 30 20 10 ELD 75 92 76 95 / 20 40 20 20 TYR 77 95 76 96 / 10 30 10 10 GGG 77 95 77 96 / 10 30 10 10 LFK 77 95 77 95 / 10 30 10 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 29/07/12
Area Forecast Discussion National Weather Service Shreveport LA 1218 PM CDT SAT JUL 9 2016 .AVIATION... Scattered -SHRA/-TSRA have been ongoing North of keld since earlier this morning, but development has shifted South to near the aforementioned terminal. This has resulted in the insertion of a TEMPO group for a few hours. A VCTS at ktxk will be maintained as activity could near that terminal as well. Otherwise, MVFR CIGS have been slow to scatter out but continues to do so. Conditions should improve to VFR within the next hour or so. Light South to Southwest and at times variable wind conditions are expected for this TAF cycle. Chances for fog appears to be low as BKN-OVC VFR decks developing overnight /can not rule out a few terminals experiencing MVFR CIGS/ will discourage adequate radiational cooling. A few computer models hint at -SHRA/-TSRA developing overnight particularly near keld and ktxk once again. Will therefore hold on to VCTS/VCSH. && .PREV DISCUSSION... /issued 1050 AM CDT SAT JUL 9 2016/ DISCUSSION... Localized cluster of convection has persisted over a good chunk of sw AR this morning. Although normally redevelopment would be expected on a hot summer day, seeing nothing on either observed 12z soundings nor on mos guidance or other data to support this convection continuing long at least more than isold coverage. Thus, will maintain low pops with chance coverage for sw AR and Se Ok and isold further south today. Temps should rise about 10 degrees with mid and a few upper 90s possible this aftn. Temps just outside convection in sw AR rising into mid and upper 80s at 10 am, leaving only a small data sparse area where rainfall may prevent temps from reaching well into 90s, but too small an area to update entire fcst attm. Will keep an eye on trends up that way but will not make any changes to fcst attm./VII/. PREV DISCUSSION... /issued 327 AM CDT SAT JUL 9 2016/ DISCUSSION... Convection over w TX/nrn AR this morning sending quite a bit of CI streaming in over the ArkLaTex. Upper ridge fcst to continue to break down today by disturbances in increasing nw flow aloft, which will aid additional convection and cloud cover for our region. This, along with lower afternoon relative humidities, will keep us out of trouble as far as a Heat Advisory is concerned. A few sites, particularly over n LA, may briefly see heat index values reach 105, but most sites will remain below. Models more aggressive with bringing a pronounced upper trof swd along the nern/ern periphery of the wwd retreating ridge into our region by later this afternoon and into Sunday. Consequently, have increased PoPs during this timeframe from previous fcst packages. Trof looks to slowly drift ewd through Monday, gradually tapering our rain chances back down to chicken 20s. Upper ridge looks to stay w of our region as the upper pattern remains somewhat unsettled through the work week. Additionally, the sea breeze appears to be making a comeback as well, which will keep PoPs in for our srn portions of the region. In other good news, temps look to hover near guidance in the mid 90s, and although arguably hot, not expecting to need advisories attm. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 77 95 78 96 / 20 30 10 10 MLU 77 92 76 94 / 20 40 20 20 DEQ 74 93 75 95 / 20 30 20 10 TXK 76 93 77 96 / 20 30 20 10 ELD 75 92 76 95 / 20 40 20 20 TYR 77 95 76 96 / 10 30 10 10 GGG 77 95 77 96 / 10 30 10 10 LFK 77 95 77 95 / 10 30 10 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 29/07/12
Area Forecast Discussion National Weather Service Shreveport LA 1218 PM CDT SAT JUL 9 2016 .AVIATION... Scattered -SHRA/-TSRA have been ongoing North of keld since earlier this morning, but development has shifted South to near the aforementioned terminal. This has resulted in the insertion of a TEMPO group for a few hours. A VCTS at ktxk will be maintained as activity could near that terminal as well. Otherwise, MVFR CIGS have been slow to scatter out but continues to do so. Conditions should improve to VFR within the next hour or so. Light South to Southwest and at times variable wind conditions are expected for this TAF cycle. Chances for fog appears to be low as BKN-OVC VFR decks developing overnight /can not rule out a few terminals experiencing MVFR CIGS/ will discourage adequate radiational cooling. A few computer models hint at -SHRA/-TSRA developing overnight particularly near keld and ktxk once again. Will therefore hold on to VCTS/VCSH. && .PREV DISCUSSION... /issued 1050 AM CDT SAT JUL 9 2016/ DISCUSSION... Localized cluster of convection has persisted over a good chunk of sw AR this morning. Although normally redevelopment would be expected on a hot summer day, seeing nothing on either observed 12z soundings nor on mos guidance or other data to support this convection continuing long at least more than isold coverage. Thus, will maintain low pops with chance coverage for sw AR and Se Ok and isold further south today. Temps should rise about 10 degrees with mid and a few upper 90s possible this aftn. Temps just outside convection in sw AR rising into mid and upper 80s at 10 am, leaving only a small data sparse area where rainfall may prevent temps from reaching well into 90s, but too small an area to update entire fcst attm. Will keep an eye on trends up that way but will not make any changes to fcst attm./VII/. PREV DISCUSSION... /issued 327 AM CDT SAT JUL 9 2016/ DISCUSSION... Convection over w TX/nrn AR this morning sending quite a bit of CI streaming in over the ArkLaTex. Upper ridge fcst to continue to break down today by disturbances in increasing nw flow aloft, which will aid additional convection and cloud cover for our region. This, along with lower afternoon relative humidities, will keep us out of trouble as far as a Heat Advisory is concerned. A few sites, particularly over n LA, may briefly see heat index values reach 105, but most sites will remain below. Models more aggressive with bringing a pronounced upper trof swd along the nern/ern periphery of the wwd retreating ridge into our region by later this afternoon and into Sunday. Consequently, have increased PoPs during this timeframe from previous fcst packages. Trof looks to slowly drift ewd through Monday, gradually tapering our rain chances back down to chicken 20s. Upper ridge looks to stay w of our region as the upper pattern remains somewhat unsettled through the work week. Additionally, the sea breeze appears to be making a comeback as well, which will keep PoPs in for our srn portions of the region. In other good news, temps look to hover near guidance in the mid 90s, and although arguably hot, not expecting to need advisories attm. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 77 95 78 96 / 20 30 10 10 MLU 77 92 76 94 / 20 40 20 20 DEQ 74 93 75 95 / 20 30 20 10 TXK 76 93 77 96 / 20 30 20 10 ELD 75 92 76 95 / 20 40 20 20 TYR 77 95 76 96 / 10 30 10 10 GGG 77 95 77 96 / 10 30 10 10 LFK 77 95 77 95 / 10 30 10 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 29/07/12
Area Forecast Discussion National Weather Service Shreveport LA 1050 AM CDT SAT JUL 9 2016 .DISCUSSION... Localized cluster of convection has persisted over a good chunk of sw AR this morning. Although normally redevelopment would be expected on a hot summer day, seeing nothing on either observed 12z soundings nor on mos guidance or other data to support this convection continuing long at least more than isold coverage. Thus, will maintain low pops with chance coverage for sw AR and Se Ok and isold further south today. Temps should rise about 10 degrees with mid and a few upper 90s possible this aftn. Temps just outside convection in sw AR rising into mid and upper 80s at 10 am, leaving only a small data sparse area where rainfall may prevent temps from reaching well into 90s, but too small an area to update entire fcst attm. Will keep an eye on trends up that way but will not make any changes to fcst attm./VII/. && .PREV DISCUSSION... /issued 629 AM CDT SAT JUL 9 2016/ AVIATION... Convection continues to develop well north of our terminal sites...across Eastern Oklahoma into Western Arkansas along an elevated thermal boundary. This activity is well elevated but should produce an outflow boundary that could come south later today and be the focus for additional convection. The most favored terminal for this activity would be the TXK/ELD terminals and for this reason...have inserted VCTS for this afternoon through the overnight hours tonight. Cannot rule out this possibility at the MLU terminal either but will allow the next fcstr to try to identify just how far south this boundary can come south towards the I-20 corridor later today. Otherwise we are dealing with some reduced vsbys in the form of patchy ground fog at the LFK terminal...this despite extensive cirrus blowoff from last nights convection across western Ok and the Tx Hill Country. Low level pressure gradient is not as strong this morning with low level flow more from the southwest. This is not allowing for the MVFR ceilings to develop much like we have seen the last several morning. Still should see a developing cu field areawide later this morning and continue into the evening hours. 13 PREV DISCUSSION... /issued 327 AM CDT SAT JUL 9 2016/ DISCUSSION... Convection over w TX/nrn AR this morning sending quite a bit of CI streaming in over the ArkLaTex. Upper ridge fcst to continue to break down today by disturbances in increasing nw flow aloft, which will aid additional convection and cloud cover for our region. This, along with lower afternoon relative humidities, will keep us out of trouble as far as a Heat Advisory is concerned. A few sites, particularly over n LA, may briefly see heat index values reach 105, but most sites will remain below. Models more aggressive with bringing a pronounced upper trof swd along the nern/ern periphery of the wwd retreating ridge into our region by later this afternoon and into Sunday. Consequently, have increased PoPs during this timeframe from previous fcst packages. Trof looks to slowly drift ewd through Monday, gradually tapering our rain chances back down to chicken 20s. Upper ridge looks to stay w of our region as the upper pattern remains somewhat unsettled through the work week. Additionally, the sea breeze appears to be making a comeback as well, which will keep PoPs in for our srn portions of the region. In other good news, temps look to hover near guidance in the mid 90s, and although arguably hot, not expecting to need advisories attm. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 97 77 95 78 / 20 20 30 10 MLU 96 77 92 76 / 20 20 40 20 DEQ 93 74 93 75 / 40 20 30 20 TXK 95 76 93 77 / 30 20 30 20 ELD 94 75 92 76 / 30 20 40 20 TYR 96 77 95 76 / 20 10 30 10 GGG 97 77 95 77 / 20 10 30 10 LFK 96 77 95 77 / 20 10 30 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$
Area Forecast Discussion National Weather Service Lake Charles LA 1050 AM CDT SAT JUL 9 2016 .DISCUSSION... 18z taf issuance. && .AVIATION... VFR & SW winds 6-10 kts this afternoon, diminishing to less than 5 kts after sunset. ISO SHRA manly confined to I-10 south late this morning, but expected to pick up in coverage this afternoon. Keeping VCSH for AEX and VCTS for BPT/LCH/LFT/ARA for this. Otherwise, VFR expected overnight into SAT morning. DML && .PRELIMINARY POINT TEMPS/POPS... AEX 95 76 94 76 / 20 20 30 20 LCH 93 79 92 79 / 20 10 30 10 LFT 94 79 93 78 / 20 10 40 20 BPT 94 79 93 78 / 20 10 30 10 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...None. && $$ AVIATION...08
Area Forecast Discussion National Weather Service Lake Charles LA 953 AM CDT SAT JUL 9 2016 .UPDATE...A few showers and a thunderstorms are ongoing across the coastal zones and temps are generally in the mid 80s area wide. This is in line with the previous forecast and no changes are needed at this time. && .PREV DISCUSSION... /issued 634 AM CDT SAT JUL 9 2016/ DISCUSSION... 09/12Z TAF Issuance. AVIATION... KLCH radar shows some isltd convection developing along the coast, while satellite images show high clouds spreading in from the west. High pres aloft will continue to weaken with the approach of a shortwave over the Red River valley, but overall expect VFR to prevail through tonight. Some isltd to widely sctd SHRA/TSRA will develop with daytime heating and kept VC mention at all sites after 15-16Z. Sfc high pres will remain over the nrn Gulf resulting in S-SW winds around 10 kt or less. 24 PREV DISCUSSION... /issued 349 AM CDT SAT JUL 9 2016/ DISCUSSION... Surface high pressure centered around Florida continues to ridge across the Gulf South and into the forecast area this early morning. With this, onshore flow off the Gulf of Mexico also continues and is allowing for ample low level moisture and humid conditions. Air temperatures are in the mid to upper 70s with relative humidity values over 90 percent. The latest upper air sounding from KLCH at 09/00z shows a little bit of a more moist atmospheric profile with higher precipitable water and mid level relative humidity values. In this humid air mass, a few nocturnal showers have formed over the Gulf and moving just onshore before dissipating, and this trend will continue through early morning. The upper level ridge that has been over the region is expected to begin retrograding back to the west today, with a short wave rotating between the upper level ridge and developing upper level trough over the eastern U.S. will help form and upper level weakness over the region, that will then persist into middle part of next week. Enough upper level ridging to hang around today to keep rain chances in the isolated category, with the majority of the activity occurring near the sea breeze during max heating. Temperatures look to be near values from the past couple of days, and likewise, afternoon max apparent temperatures will be about the same, and from 103F to 107F degrees, and below advisory criteria. As weakness develop aloft, rain chances will increase beginning on Sunday, to chance category, and near climo values, as typical summertime scattered, mainly afternoon, showers and thunderstorms will be possible into next week. With the increase in cloud cover and convection, temperatures will also be in line with climo values. Rua MARINE... Mainly southwest winds at 10 to 15 knots occurring across the coastal waters this early morning...with a few nocturnal showers. Surface high pressure is centered around Florida and is ridging westward across the northern Gulf of Mexico into the coastal waters. This general weather pattern will continue for the remainder of the weekend into early next week. Therefore, light to moderate onshore flow will also continue with seas mainly 1 to 3 feet. The chances for showers and thunderstorms will also be on the increase as a weakness aloft develops over the region. Rua && .PRELIMINARY POINT TEMPS/POPS... AEX 95 76 94 76 / 20 20 30 20 LCH 93 79 92 79 / 20 10 30 10 LFT 94 79 93 78 / 20 10 40 20 BPT 94 79 93 78 / 20 10 30 10 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...None. && $$ PUBLIC...05
Area Forecast Discussion National Weather Service Lake Charles LA 953 AM CDT SAT JUL 9 2016 .UPDATE...A few showers and a thunderstorms are ongoing across the coastal zones and temps are generally in the mid 80s area wide. This is in line with the previous forecast and no changes are needed at this time. && .PREV DISCUSSION... /issued 634 AM CDT SAT JUL 9 2016/ DISCUSSION... 09/12Z TAF Issuance. AVIATION... KLCH radar shows some isltd convection developing along the coast, while satellite images show high clouds spreading in from the west. High pres aloft will continue to weaken with the approach of a shortwave over the Red River valley, but overall expect VFR to prevail through tonight. Some isltd to widely sctd SHRA/TSRA will develop with daytime heating and kept VC mention at all sites after 15-16Z. Sfc high pres will remain over the nrn Gulf resulting in S-SW winds around 10 kt or less. 24 PREV DISCUSSION... /issued 349 AM CDT SAT JUL 9 2016/ DISCUSSION... Surface high pressure centered around Florida continues to ridge across the Gulf South and into the forecast area this early morning. With this, onshore flow off the Gulf of Mexico also continues and is allowing for ample low level moisture and humid conditions. Air temperatures are in the mid to upper 70s with relative humidity values over 90 percent. The latest upper air sounding from KLCH at 09/00z shows a little bit of a more moist atmospheric profile with higher precipitable water and mid level relative humidity values. In this humid air mass, a few nocturnal showers have formed over the Gulf and moving just onshore before dissipating, and this trend will continue through early morning. The upper level ridge that has been over the region is expected to begin retrograding back to the west today, with a short wave rotating between the upper level ridge and developing upper level trough over the eastern U.S. will help form and upper level weakness over the region, that will then persist into middle part of next week. Enough upper level ridging to hang around today to keep rain chances in the isolated category, with the majority of the activity occurring near the sea breeze during max heating. Temperatures look to be near values from the past couple of days, and likewise, afternoon max apparent temperatures will be about the same, and from 103F to 107F degrees, and below advisory criteria. As weakness develop aloft, rain chances will increase beginning on Sunday, to chance category, and near climo values, as typical summertime scattered, mainly afternoon, showers and thunderstorms will be possible into next week. With the increase in cloud cover and convection, temperatures will also be in line with climo values. Rua MARINE... Mainly southwest winds at 10 to 15 knots occurring across the coastal waters this early morning...with a few nocturnal showers. Surface high pressure is centered around Florida and is ridging westward across the northern Gulf of Mexico into the coastal waters. This general weather pattern will continue for the remainder of the weekend into early next week. Therefore, light to moderate onshore flow will also continue with seas mainly 1 to 3 feet. The chances for showers and thunderstorms will also be on the increase as a weakness aloft develops over the region. Rua && .PRELIMINARY POINT TEMPS/POPS... AEX 95 76 94 76 / 20 20 30 20 LCH 93 79 92 79 / 20 10 30 10 LFT 94 79 93 78 / 20 10 40 20 BPT 94 79 93 78 / 20 10 30 10 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...None. && $$ PUBLIC...05
Area Forecast Discussion National Weather Service New Orleans LA 837 AM CDT SAT JUL 9 2016 .SOUNDING DISCUSSION... There were not any issues with the upper air release this morning. The 12z sounding depicted a moist and unstable atmospheric profile that was similar to what was observed yesterday. The precipitable water value was 1.88 inches. Winds were mainly light westerly up to 500 mb, and then north to northeast above that level. 11 && .PRELIMINARY POINT TEMPS/POPS... MCB 93 74 91 73 / 30 20 50 20 BTR 94 76 93 75 / 30 20 50 20 ASD 94 76 91 76 / 40 20 50 20 MSY 94 79 91 78 / 40 20 50 20 GPT 92 76 90 77 / 40 20 50 20 PQL 93 76 91 75 / 30 30 40 30 && .LIX Watches/Warnings/Advisories... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion National Weather Service Lake Charles LA 634 AM CDT SAT JUL 9 2016 .DISCUSSION... 09/12Z TAF Issuance. && .AVIATION... KLCH radar shows some isltd convection developing along the coast, while satellite images show high clouds spreading in from the west. High pres aloft will continue to weaken with the approach of a shortwave over the Red River valley, but overall expect VFR to prevail through tonight. Some isltd to widely sctd SHRA/TSRA will develop with daytime heating and kept VC mention at all sites after 15-16Z. Sfc high pres will remain over the nrn Gulf resulting in S-SW winds around 10 kt or less. 24 && .PREV DISCUSSION... /issued 349 AM CDT SAT JUL 9 2016/ DISCUSSION... Surface high pressure centered around Florida continues to ridge across the Gulf South and into the forecast area this early morning. With this, onshore flow off the Gulf of Mexico also continues and is allowing for ample low level moisture and humid conditions. Air temperatures are in the mid to upper 70s with relative humidity values over 90 percent. The latest upper air sounding from KLCH at 09/00z shows a little bit of a more moist atmospheric profile with higher precipitable water and mid level relative humidity values. In this humid air mass, a few nocturnal showers have formed over the Gulf and moving just onshore before dissipating, and this trend will continue through early morning. The upper level ridge that has been over the region is expected to begin retrograding back to the west today, with a short wave rotating between the upper level ridge and developing upper level trough over the eastern U.S. will help form and upper level weakness over the region, that will then persist into middle part of next week. Enough upper level ridging to hang around today to keep rain chances in the isolated category, with the majority of the activity occurring near the sea breeze during max heating. Temperatures look to be near values from the past couple of days, and likewise, afternoon max apparent temperatures will be about the same, and from 103F to 107F degrees, and below advisory criteria. As weakness develop aloft, rain chances will increase beginning on Sunday, to chance category, and near climo values, as typical summertime scattered, mainly afternoon, showers and thunderstorms will be possible into next week. With the increase in cloud cover and convection, temperatures will also be in line with climo values. Rua MARINE... Mainly southwest winds at 10 to 15 knots occurring across the coastal waters this early morning...with a few nocturnal showers. Surface high pressure is centered around Florida and is ridging westward across the northern Gulf of Mexico into the coastal waters. This general weather pattern will continue for the remainder of the weekend into early next week. Therefore, light to moderate onshore flow will also continue with seas mainly 1 to 3 feet. The chances for showers and thunderstorms will also be on the increase as a weakness aloft develops over the region. Rua && .PRELIMINARY POINT TEMPS/POPS... AEX 95 76 94 76 / 20 20 30 20 LCH 93 79 92 79 / 20 10 30 10 LFT 94 79 93 78 / 20 10 40 20 BPT 94 79 93 78 / 20 10 30 10 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...None. && $$ AVIATION...24
Area Forecast Discussion National Weather Service Lake Charles LA 634 AM CDT SAT JUL 9 2016 .DISCUSSION... 09/12Z TAF Issuance. && .AVIATION... KLCH radar shows some isltd convection developing along the coast, while satellite images show high clouds spreading in from the west. High pres aloft will continue to weaken with the approach of a shortwave over the Red River valley, but overall expect VFR to prevail through tonight. Some isltd to widely sctd SHRA/TSRA will develop with daytime heating and kept VC mention at all sites after 15-16Z. Sfc high pres will remain over the nrn Gulf resulting in S-SW winds around 10 kt or less. 24 && .PREV DISCUSSION... /issued 349 AM CDT SAT JUL 9 2016/ DISCUSSION... Surface high pressure centered around Florida continues to ridge across the Gulf South and into the forecast area this early morning. With this, onshore flow off the Gulf of Mexico also continues and is allowing for ample low level moisture and humid conditions. Air temperatures are in the mid to upper 70s with relative humidity values over 90 percent. The latest upper air sounding from KLCH at 09/00z shows a little bit of a more moist atmospheric profile with higher precipitable water and mid level relative humidity values. In this humid air mass, a few nocturnal showers have formed over the Gulf and moving just onshore before dissipating, and this trend will continue through early morning. The upper level ridge that has been over the region is expected to begin retrograding back to the west today, with a short wave rotating between the upper level ridge and developing upper level trough over the eastern U.S. will help form and upper level weakness over the region, that will then persist into middle part of next week. Enough upper level ridging to hang around today to keep rain chances in the isolated category, with the majority of the activity occurring near the sea breeze during max heating. Temperatures look to be near values from the past couple of days, and likewise, afternoon max apparent temperatures will be about the same, and from 103F to 107F degrees, and below advisory criteria. As weakness develop aloft, rain chances will increase beginning on Sunday, to chance category, and near climo values, as typical summertime scattered, mainly afternoon, showers and thunderstorms will be possible into next week. With the increase in cloud cover and convection, temperatures will also be in line with climo values. Rua MARINE... Mainly southwest winds at 10 to 15 knots occurring across the coastal waters this early morning...with a few nocturnal showers. Surface high pressure is centered around Florida and is ridging westward across the northern Gulf of Mexico into the coastal waters. This general weather pattern will continue for the remainder of the weekend into early next week. Therefore, light to moderate onshore flow will also continue with seas mainly 1 to 3 feet. The chances for showers and thunderstorms will also be on the increase as a weakness aloft develops over the region. Rua && .PRELIMINARY POINT TEMPS/POPS... AEX 95 76 94 76 / 20 20 30 20 LCH 93 79 92 79 / 20 10 30 10 LFT 94 79 93 78 / 20 10 40 20 BPT 94 79 93 78 / 20 10 30 10 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...None. && $$ AVIATION...24
Area Forecast Discussion National Weather Service Shreveport LA 629 AM CDT SAT JUL 9 2016 .AVIATION... Convection continues to develop well north of our terminal sites...across Eastern Oklahoma into Western Arkansas along an elevated thermal boundary. This activity is well elevated but should produce an outflow boundary that could come south later today and be the focus for additional convection. The most favored terminal for this activity would be the TXK/ELD terminals and for this reason...have inserted VCTS for this afternoon through the overnight hours tonight. Cannot rule out this possibility at the MLU terminal either but will allow the next fcstr to try to identify just how far south this boundary can come south towards the I-20 corridor later today. Otherwise we are dealing with some reduced vsbys in the form of patchy ground fog at the LFK terminal...this despite extensive cirrus blowoff from last nights convection across western Ok and the Tx Hill Country. Low level pressure gradient is not as strong this morning with low level flow more from the southwest. This is not allowing for the MVFR ceilings to develop much like we have seen the last several morning. Still should see a developing cu field areawide later this morning and continue into the evening hours. 13 && .PREV DISCUSSION... /issued 327 AM CDT SAT JUL 9 2016/ DISCUSSION... Convection over w TX/nrn AR this morning sending quite a bit of CI streaming in over the ArkLaTex. Upper ridge fcst to continue to break down today by disturbances in increasing nw flow aloft, which will aid additional convection and cloud cover for our region. This, along with lower afternoon relative humidities, will keep us out of trouble as far as a Heat Advisory is concerned. A few sites, particularly over n LA, may briefly see heat index values reach 105, but most sites will remain below. Models more aggressive with bringing a pronounced upper trof swd along the nern/ern periphery of the wwd retreating ridge into our region by later this afternoon and into Sunday. Consequently, have increased PoPs during this timeframe from previous fcst packages. Trof looks to slowly drift ewd through Monday, gradually tapering our rain chances back down to chicken 20s. Upper ridge looks to stay w of our region as the upper pattern remains somewhat unsettled through the work week. Additionally, the sea breeze appears to be making a comeback as well, which will keep PoPs in for our srn portions of the region. In other good news, temps look to hover near guidance in the mid 90s, and although arguably hot, not expecting to need advisories attm. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 97 77 95 78 / 20 20 30 10 MLU 96 77 92 76 / 20 20 40 20 DEQ 93 74 93 75 / 40 20 30 20 TXK 95 76 93 77 / 30 20 30 20 ELD 94 75 92 76 / 30 20 40 20 TYR 96 77 95 76 / 20 10 30 10 GGG 97 77 95 77 / 20 10 30 10 LFK 96 77 95 77 / 20 10 30 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 12/13
Area Forecast Discussion National Weather Service Shreveport LA 629 AM CDT SAT JUL 9 2016 .AVIATION... Convection continues to develop well north of our terminal sites...across Eastern Oklahoma into Western Arkansas along an elevated thermal boundary. This activity is well elevated but should produce an outflow boundary that could come south later today and be the focus for additional convection. The most favored terminal for this activity would be the TXK/ELD terminals and for this reason...have inserted VCTS for this afternoon through the overnight hours tonight. Cannot rule out this possibility at the MLU terminal either but will allow the next fcstr to try to identify just how far south this boundary can come south towards the I-20 corridor later today. Otherwise we are dealing with some reduced vsbys in the form of patchy ground fog at the LFK terminal...this despite extensive cirrus blowoff from last nights convection across western Ok and the Tx Hill Country. Low level pressure gradient is not as strong this morning with low level flow more from the southwest. This is not allowing for the MVFR ceilings to develop much like we have seen the last several morning. Still should see a developing cu field areawide later this morning and continue into the evening hours. 13 && .PREV DISCUSSION... /issued 327 AM CDT SAT JUL 9 2016/ DISCUSSION... Convection over w TX/nrn AR this morning sending quite a bit of CI streaming in over the ArkLaTex. Upper ridge fcst to continue to break down today by disturbances in increasing nw flow aloft, which will aid additional convection and cloud cover for our region. This, along with lower afternoon relative humidities, will keep us out of trouble as far as a Heat Advisory is concerned. A few sites, particularly over n LA, may briefly see heat index values reach 105, but most sites will remain below. Models more aggressive with bringing a pronounced upper trof swd along the nern/ern periphery of the wwd retreating ridge into our region by later this afternoon and into Sunday. Consequently, have increased PoPs during this timeframe from previous fcst packages. Trof looks to slowly drift ewd through Monday, gradually tapering our rain chances back down to chicken 20s. Upper ridge looks to stay w of our region as the upper pattern remains somewhat unsettled through the work week. Additionally, the sea breeze appears to be making a comeback as well, which will keep PoPs in for our srn portions of the region. In other good news, temps look to hover near guidance in the mid 90s, and although arguably hot, not expecting to need advisories attm. /12/ && .PRELIMINARY POINT TEMPS/POPS... SHV 97 77 95 78 / 20 20 30 10 MLU 96 77 92 76 / 20 20 40 20 DEQ 93 74 93 75 / 40 20 30 20 TXK 95 76 93 77 / 30 20 30 20 ELD 94 75 92 76 / 30 20 40 20 TYR 96 77 95 76 / 20 10 30 10 GGG 97 77 95 77 / 20 10 30 10 LFK 96 77 95 77 / 20 10 30 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 12/13
Area Forecast Discussion National Weather Service Lake Charles LA 349 AM CDT SAT JUL 9 2016 .DISCUSSION... Surface high pressure centered around Florida continues to ridge across the Gulf South and into the forecast area this early morning. With this, onshore flow off the Gulf of Mexico also continues and is allowing for ample low level moisture and humid conditions. Air temperatures are in the mid to upper 70s with relative humidity values over 90 percent. The latest upper air sounding from KLCH at 09/00z shows a little bit of a more moist atmospheric profile with higher precipitable water and mid level relative humidity values. In this humid air mass, a few nocturnal showers have formed over the Gulf and moving just onshore before dissipating, and this trend will continue through early morning. The upper level ridge that has been over the region is expected to begin retrograding back to the west today, with a short wave rotating between the upper level ridge and developing upper level trough over the eastern U.S. will help form and upper level weakness over the region, that will then persist into middle part of next week. Enough upper level ridging to hang around today to keep rain chances in the isolated category, with the majority of the activity occurring near the sea breeze during max heating. Temperatures look to be near values from the past couple of days, and likewise, afternoon max apparent temperatures will be about the same, and from 103F to 107F degrees, and below advisory criteria. As weakness develop aloft, rain chances will increase beginning on Sunday, to chance category, and near climo values, as typical summertime scattered, mainly afternoon, showers and thunderstorms will be possible into next week. With the increase in cloud cover and convection, temperatures will also be in line with climo values. Rua && .MARINE... Mainly southwest winds at 10 to 15 knots occurring across the coastal waters this early morning...with a few nocturnal showers. Surface high pressure is centered around Florida and is ridging westward across the northern Gulf of Mexico into the coastal waters. This general weather pattern will continue for the remainder of the weekend into early next week. Therefore, light to moderate onshore flow will also continue with seas mainly 1 to 3 feet. The chances for showers and thunderstorms will also be on the increase as a weakness aloft develops over the region. Rua && .PRELIMINARY POINT TEMPS/POPS... AEX 95 76 94 76 / 20 20 30 20 LCH 93 79 92 79 / 20 10 30 10 LFT 94 79 93 78 / 20 10 40 20 BPT 94 79 93 78 / 20 10 30 10 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...None. && $$ PUBLIC...07
Area Forecast Discussion National Weather Service Shreveport LA 327 AM CDT SAT JUL 9 2016 .DISCUSSION... Convection over w TX/nrn AR this morning sending quite a bit of CI streaming in over the ArkLaTex. Upper ridge fcst to continue to break down today by disturbances in increasing nw flow aloft, which will aid additional convection and cloud cover for our region. This, along with lower afternoon relative humidities, will keep us out of trouble as far as a Heat Advisory is concerned. A few sites, particularly over n LA, may briefly see heat index values reach 105, but most sites will remain below. Models more aggressive with bringing a pronounced upper trof swd along the nern/ern periphery of the wwd retreating ridge into our region by later this afternoon and into Sunday. Consequently, have increased PoPs during this timeframe from previous fcst packages. Trof looks to slowly drift ewd through Monday, gradually tapering our rain chances back down to chicken 20s. Upper ridge looks to stay w of our region as the upper pattern remains somewhat unsettled through the work week. Additionally, the sea breeze appears to be making a comeback as well, which will keep PoPs in for our srn portions of the region. In other good news, temps look to hover near guidance in the mid 90s, and although arguably hot, not expecting to need advisories attm. /12/ && .PREV DISCUSSION... /issued 1200 AM CDT SAT JUL 9 2016/ AVIATION... Mostly VFR conditions will continue through much of the 09/06Z TAF period. Still seeing a bit of a sct cu field that has redeveloped over NE TX/N LA/SW AR...with a dense cirrus shield spilling SE into the region from convection over Cntrl/Ern OK into Nrn AR. Could still see low MVFR cigs develop over the wrn sections of E TX as well as Deep E TX after 10Z...with the potential for isolated areas of LIFR cigs/patchy FG near LFK around daybreak. Any cigs should gradually lift and scatter out by 15-16Z over E TX...with a sct cu field expected to develop elsewhere by/after 18Z. Depending on if the convection over Ncntrl AR is able to send any mesoscale bndrys SSW into Cntrl AR...additional sct convection may be focused farther SSW Saturday afternoon as a weak upper trough axis slides S into extreme NE TX/SW AR late in the day. For now...have left out mention of VCTS for the SW AR terminals given some uncertainty although isolated to possibly sct convection may affect SW AR during the afternoon/evening. S winds 3-7kts tonight will become WSW 6-10kts after 15Z. /15/ && .PRELIMINARY POINT TEMPS/POPS... SHV 97 77 95 78 / 20 20 20 10 MLU 96 77 92 76 / 20 20 30 20 DEQ 93 74 93 75 / 40 20 30 20 TXK 95 76 93 77 / 30 20 30 20 ELD 94 75 92 76 / 30 20 30 20 TYR 96 77 95 76 / 20 10 20 10 GGG 97 77 95 77 / 20 10 20 10 LFK 96 77 95 77 / 20 10 20 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 12
Area Forecast Discussion National Weather Service New Orleans LA 247 AM CDT SAT JUL 9 2016 .SYNOPSIS... Weak upper ridging beginning to build back westward toward the Rockies with Bermuda surface high continuing to control the weather across the northern Gulf of Mexico. Airmass has been a little more conducive to convection over the past 24 hours than in previous days. Afternoon convection yesterday provided some brief relief from the oppressive conditions as temperatures fell into the upper 70s. This morning, there is again isolated convection over the coastal waters and along the Louisiana coast. Temperatures at 2 am ranged from the mid 70s to lower 80s across the area. && .SHORT TERM... Impulse currently over the middle Mississippi River Valley will drift southward into the area over the next 48 hours. The slightly cooler mid level temperatures associated with this feature should allow areal coverage of afternoon convection to increase for the next few days from what has been seen even on Friday. Will be carrying 30-40 percent pops today, 40-60 percent on Sunday, and 40-50 percent on Monday. Most convection should dissipate near, or shortly after, sunset. The additional convection and associated cloud cover should hold high temperatures down a few degrees from earlier in the week with most areas in the 90 to 95 range. Can not rule out one or two locations nearing the Heat Advisory threshold of a Heat Index of 108 degrees briefly before convection develops, but threat not large enough to justify an additional Heat Advisory. && .LONG TERM... If there is going to be a dry day during the extended period, it might be Tuesday. Overall, expect daily development of scattered thunderstorms during the late morning and afternoon hours, dying out around sunset over land areas. Should not be much day to day change in temperatures outside of areas that receive convection around midday. && .AVIATION... Ceilings will begin to develop today over much of the area starting out at around BKN015 during the morning, lifting to BKN040 then to BKN050. This will be mixed with SCT sky cover as well. A few sh/ts should also be around. Will set a few TEMPO groups for those that should see the best chance of getting a TS. This should be terminals from MCB to MSY eastward. Once again ceilings should clear out for much of the overnight hours. && .MARINE... Surface high that has been over the northern gulf will move east slightly. It will still keep flow onshore throughout the forecast. But with a more southeasterly flow coupled with the weaker higher inversion due to the high backing off, sh/ts will begin to develop a little easier. Will continue to see the typical diurnal wind increase/decrease as nocturnal winds rise to 10 to 15 knots which will carry over into the morning hours and then drop down the rest of the day closer to 10 knots or slightly less. Nocturnal sh/ts will also develop during the late night and early morning hours through the next several days. && .DECISION SUPPORT... DSS code: Green. Deployed: None. Activation: None. Activities: None. Decision Support Services (DSS) Code Legend Green = No weather impacts that require action. Blue = Long-fused watch, warning, or advisory in effect or high visibility event. Yellow = Heightened impacts with short-fused watch, warning or advisory issuances; radar support. Orange = High Impacts; Slight to Moderate risk severe; nearby tropical events; HazMat or other large episodes. Red = Full engagement for Moderate risk of severe and/or direct tropical threats; Events of National Significance. && .PRELIMINARY POINT TEMPS/POPS... MCB 93 74 91 73 / 30 20 50 20 BTR 94 76 93 75 / 30 20 50 20 ASD 94 76 91 76 / 40 20 50 20 MSY 94 79 91 78 / 40 20 50 20 GPT 92 76 90 77 / 40 20 50 20 PQL 93 76 91 75 / 30 30 40 30 && .LIX Watches/Warnings/Advisories... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion National Weather Service Lake Charles LA 1217 AM CDT SAT JUL 9 2016 .DISCUSSION... Mstly clr skies thru the ovrnght hrs. Otherwise VFR most lctns although 024 ceilings can be xpcd alng the cst at times. && .PREV DISCUSSION... /issued 937 PM CDT FRI JUL 8 2016/ DISCUSSION... Current forecast is on target. Updated ZFP sent to remove first period temporal wording. No changes to the grids at this time. 13 PREV DISCUSSION... /issued 637 PM CDT FRI JUL 8 2016/ AVIATION... A few storms remaining ovr srn La this eve. These storms are xpcd to fall apart ovr the nxt hr or so w/ skies remaining mstly clr thru the ovrnght. VFR wx. PREV DISCUSSION... /issued 314 PM CDT FRI JUL 8 2016/ DISCUSSION...The area remains on the edge of an upper level ridge that is centered over Northern Mexico, however the eastern flank over the northern gulf coast is gradually weakening. There is a slight increase in convection today when compared to over the past couple of days as the ridge has somewhat weakened. This trend will continue into the weekend. While widespread showers and storms are not expected by Sunday, a healthy dose of scattered convection along a sea breeze may occur as a modest upper trough moves across the eastern sections of the country. As convection and cloud cover increase high temps will also remain at or near climo values. Next week the area will remain on the eastern edge of the upper ridge which will allow for isolated to scattered diurnal convection. The sub-tropical ridge will also remain anchored over the Atlantic keeping the humid south flow in place. MARINE...A ridge will remain stretched from the Atlantic into the northern gulf into next week. This will keep a light to moderate onshore flow in place. && .PRELIMINARY POINT TEMPS/POPS... AEX 95 77 96 76 / 20 10 20 10 LCH 93 79 93 79 / 20 10 20 10 LFT 94 78 93 78 / 30 10 30 10 BPT 94 79 93 79 / 20 10 20 10 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...None. && $$ PUBLIC...19
Area Forecast Discussion...UPDATED National Weather Service Shreveport LA 1200 AM CDT SAT JUL 9 2016 .AVIATION... Mostly VFR conditions will continue through much of the 09/06Z TAF period. Still seeing a bit of a sct cu field that has redeveloped over NE TX/N LA/SW AR...with a dense cirrus shield spilling SE into the region from convection over Cntrl/Ern OK into Nrn AR. Could still see low MVFR cigs develop over the wrn sections of E TX as well as Deep E TX after 10Z...with the potential for isolated areas of LIFR cigs/patchy FG near LFK around daybreak. Any cigs should gradually lift and scatter out by 15-16Z over E TX...with a sct cu field expected to develop elsewhere by/after 18Z. Depending on if the convection over Ncntrl AR is able to send any mesoscale bndrys SSW into Cntrl AR...additional sct convection may be focused farther SSW Saturday afternoon as a weak upper trough axis slides S into extreme NE TX/SW AR late in the day. For now...have left out mention of VCTS for the SW AR terminals given some uncertainty although isolated to possibly sct convection may affect SW AR during the afternoon/evening. S winds 3-7kts tonight will become WSW 6-10kts after 15Z. /15/ && .PREV DISCUSSION... /issued 1017 PM CDT FRI JUL 8 2016/ DISCUSSION... Large complex of showers and thunderstorms continues to slowly advance southward across eastern Oklahoma into extreme western Arkansas. This convection will likely diminish in coverage and intensity through the overnight hours so have trimmed back pops slightly across our northern sections through midnight. However, additional development cannot be ruled through daybreak with increasing upper troughing beginning to work southward from the Ozarks. So slight chance/low chance pops have been adjusted slightly across our northern zones for the early morning hours. Otherwise, the remainder of the forecast was left intact. All updated text products will be out shortly. /19/ && .PRELIMINARY POINT TEMPS/POPS... SHV 77 95 77 96 / 10 10 10 20 MLU 77 94 76 94 / 10 30 20 30 DEQ 76 93 75 93 / 30 30 20 30 TXK 77 95 77 94 / 20 20 20 30 ELD 77 94 76 94 / 20 30 20 30 TYR 77 96 77 96 / 10 10 10 10 GGG 77 96 77 96 / 10 10 10 10 LFK 77 95 77 96 / 10 20 0 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 15
Area Forecast Discussion National Weather Service New Orleans LA 1156 PM CDT FRI JUL 8 2016 .AVIATION...VFR conditions will continue to dominate for the rest of the night and through Saturday morning. The only exception may be another round of MVFR to IFR conditions due to BR/light FG at KMCB early in the morning. CU should begin to develop around 14/15z and expect scattered TSRA before 18z. && .LIX Watches/Warnings/Advisories... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion National Weather Service Shreveport LA 1017 PM CDT FRI JUL 8 2016 .DISCUSSION... Large complex of showers and thunderstorms continues to slowly advance southward across eastern Oklahoma into extreme western Arkansas. This convection will likely diminish in coverage and intensity through the overnight hours so have trimmed back pops slightly across our northern sections through midnight. However, additional development cannot be ruled through daybreak with increasing upper troughing beginning to work southward from the Ozarks. So slight chance/low chance pops have been adjusted slightly across our northern zones for the early morning hours. Otherwise, the remainder of the forecast was left intact. All updated text products will be out shortly. /19/ && .PREV DISCUSSION... /issued 650 PM CDT FRI JUL 8 2016/ AVIATION... VFR conditions will continue through much of the 09/00Z TAF period. The cu field will diminish shortly after sunset...with the cirrus shield expected to gradually increase from the NW...associated with sct strong convection over NW TX/Cntrl OK. May see low MVFR/IFR cigs develop just before daybreak Saturday over portions of the Wrn sections of E TX...with patchy FG/LIFR cigs developing near LFK. However...these cigs should be more scarce than what has developed each morning this week. Any low cigs that develop will scatter out by 15-16Z...with a sct cu field developing by midday elsewhere beneath cirrus cigs. Sct convection is expected to develop Saturday afternoon over Cntrl AR and may backbuild SW into the NE sections of SW AR...but should remain NNE of the TXK/ELD terminals. S winds 4-8kts tonight will become SSW after 15Z. /15/ && .PRELIMINARY POINT TEMPS/POPS... SHV 77 95 77 96 / 10 10 10 20 MLU 77 94 76 94 / 10 30 20 30 DEQ 76 93 75 93 / 30 30 20 30 TXK 77 95 77 94 / 20 20 20 30 ELD 77 94 76 94 / 20 30 20 30 TYR 77 96 77 96 / 10 10 10 10 GGG 77 96 77 96 / 10 10 10 10 LFK 77 95 77 96 / 10 20 0 10 && .SHV Watches/Warnings/Advisories... AR...None. LA...None. OK...None. TX...None. && $$ 19/15
Area Forecast Discussion National Weather Service Lake Charles LA 937 PM CDT FRI JUL 8 2016 .DISCUSSION... Current forecast is on target. Updated ZFP sent to remove first period temporal wording. No changes to the grids at this time. 13 && .PREV DISCUSSION... /issued 637 PM CDT FRI JUL 8 2016/ AVIATION... A few storms remaining ovr srn La this eve. These storms are xpcd to fall apart ovr the nxt hr or so w/ skies remaining mstly clr thru the ovrnght. VFR wx. PREV DISCUSSION... /issued 314 PM CDT FRI JUL 8 2016/ DISCUSSION...The area remains on the edge of an upper level ridge that is centered over Northern Mexico, however the eastern flank over the northern gulf coast is gradually weakening. There is a slight increase in convection today when compared to over the past couple of days as the ridge has somewhat weakened. This trend will continue into the weekend. While widespread showers and storms are not expected by Sunday, a healthy dose of scattered convection along a sea breeze may occur as a modest upper trough moves across the eastern sections of the country. As convection and cloud cover increase high temps will also remain at or near climo values. Next week the area will remain on the eastern edge of the upper ridge which will allow for isolated to scattered diurnal convection. The sub-tropical ridge will also remain anchored over the Atlantic keeping the humid south flow in place. MARINE...A ridge will remain stretched from the Atlantic into the northern gulf into next week. This will keep a light to moderate onshore flow in place. && .PRELIMINARY POINT TEMPS/POPS... AEX 77 96 76 95 / 10 20 10 20 LCH 79 93 79 93 / 10 20 10 30 LFT 78 93 78 93 / 10 30 10 40 BPT 79 93 79 93 / 10 20 10 30 && .LCH Watches/Warnings/Advisories... LA...None. TX...None. GM...None. && $$
Area Forecast Discussion National Weather Service New Orleans LA 846 PM CDT FRI JUL 8 2016 .SOUNDING DISCUSSION... No problems with the flight this evening that lasted 103 minutes and burst 29 miles downrange southwest over western Lake Ponchartrain, observed pretty close to a narrow crescent moon at termination. Pretty unstable looking sounding with -8 lifted index and 3749 J/kg CAPE, precipitable water of 1.85 inches. Very high wet bulb zero around 15kft, and very high tropopause around 94. Moisture profile shows about 5-7 degree departures surface to about 450 mb, then a dry layer to about 375 mb, before constricting aloft at residual cirrus level from earlier cumulonimbi. Winds were S-SW 10-15 kt surface to about 15kft, then a layer of N 5-10kt to about 26kft, then NE 15-35kt aloft through tropopause. 24/RR && .PREV DISCUSSION... /issued 406 PM CDT FRI JUL 8 2016/ Discussion... Current upper level synopsis shows a ridge centered near the northern Texas panhandle and a trough over the eastern third of the country. A surface inflection of the Bermuda ridge does extend across Florida to the western Gulf of Mexico. Current convection has already begun to wane and will diminish over the next few hours with loss of daytime heating. Many locations did get a brief cool down from showers and storms but that soil moisture may convert back into higher dewpoints overnight. Even though New Orleans dropped below 80 for the first time in several days after a thunderstorm today (it has since warmed back into the upper 80s) not sure the temperature will fall below 80 tonight. Decided to hold off on re-issuing the heat advisory to allow overnight shift to monitor lows in addition to thinking that there will be more coverage tomorrow. And speaking of the forecast Saturday...the upper ridge to the west that extends over the CWA will begin to weaken locally and retrograde westward. This decreased subsidence with possibly slightly more column moisture should result in more numerous showers and thunderstorms. This will moreso be the case going into Sunday as a weak trough develops from the Tennessee Valley, extending southwestward towards the CWA. Thus have increased pops on both days this weekend to 20- 40% Saturday and 50% Sunday. Not much change expected throughout next week in terms of rain chances. Daily afternoon pops should be 30-40% each day the local area will be under a shear zone between Bermuda ridge that moves into the western Atlantic and a trough moving east across the northern half of the country. MEFFER AVIATION... VFR conditions are expected to dominate for the rest of this afternoon through Saturday morning. The only exceptions will be briefly lower conditions due isolated SHRA/TSRA, affecting KMSY, KNEW, KASD, KGPT and KHUM mainly through 23z. There may also be another round of MVFR to IFR conditions due to BR/light fog at KMCB late tonight/early Saturday morning. MARINE... Bermuda surface ridge extending across the Gulf of Mexico will keep flow onshore throughout the forecast period. The local coastal waters will continue to see the typical diurnal wind increase/decrease as nocturnal winds rise to 10 to 15 knots which will carry over into the morning hours and then drop down the rest of the day closer to 10 knots or slightly less. This should continue into the weekend. Nocturnal sh/ts will also develop during the late night and early morning hours through the next several days. Winds will begin to shift to a more SE direction by Sunday as the ridge shifts northward. DECISION SUPPORT... DSS code: Green. Deployed: None. Activation: None. Activities: None. Decision Support Services (DSS) Code Legend Green = No weather impacts that require action. Blue = Long-fused watch, warning, or advisory in effect or high visibility event. Yellow = Heightened impacts with short-fused watch, warning or advisory issuances; radar support. Orange = High Impacts; Slight to Moderate risk severe; nearby tropical events; HazMat or other large episodes. Red = Full engagement for Moderate risk of severe and/or direct tropical threats; Events of National Significance. && .PRELIMINARY POINT TEMPS/POPS... MCB 76 93 74 94 / 10 20 20 50 BTR 77 94 76 94 / 10 20 10 50 ASD 79 94 76 93 / 10 40 20 50 MSY 81 94 79 92 / 10 40 10 50 GPT 80 92 76 91 / 10 30 20 40 PQL 78 93 76 94 / 10 30 20 40 && .LIX Watches/Warnings/Advisories... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion National Weather Service New Orleans LA 846 PM CDT FRI JUL 8 2016 .SOUNDING DISCUSSION... No problems with the flight this evening that lasted 103 minutes and burst 29 miles downrange southwest over western Lake Ponchartrain, observed pretty close to a narrow crescent moon at termination. Pretty unstable looking sounding with -8 lifted index and 3749 J/kg CAPE, precipitable water of 1.85 inches. Very high wet bulb zero around 15kft, and very high tropopause around 94. Moisture profile shows about 5-7 degree departures surface to about 450 mb, then a dry layer to about 375 mb, before constricting aloft at residual cirrus level from earlier cumulonimbi. Winds were S-SW 10-15 kt surface to about 15kft, then a layer of N 5-10kt to about 26kft, then NE 15-35kt aloft through tropopause. 24/RR && .PREV DISCUSSION... /issued 406 PM CDT FRI JUL 8 2016/ Discussion... Current upper level synopsis shows a ridge centered near the northern Texas panhandle and a trough over the eastern third of the country. A surface inflection of the Bermuda ridge does extend across Florida to the western Gulf of Mexico. Current convection has already begun to wane and will diminish over the next few hours with loss of daytime heating. Many locations did get a brief cool down from showers and storms but that soil moisture may convert back into higher dewpoints overnight. Even though New Orleans dropped below 80 for the first time in several days after a thunderstorm today (it has since warmed back into the upper 80s) not sure the temperature will fall below 80 tonight. Decided to hold off on re-issuing the heat advisory to allow overnight shift to monitor lows in addition to thinking that there will be more coverage tomorrow. And speaking of the forecast Saturday...the upper ridge to the west that extends over the CWA will begin to weaken locally and retrograde westward. This decreased subsidence with possibly slightly more column moisture should result in more numerous showers and thunderstorms. This will moreso be the case going into Sunday as a weak trough develops from the Tennessee Valley, extending southwestward towards the CWA. Thus have increased pops on both days this weekend to 20- 40% Saturday and 50% Sunday. Not much change expected throughout next week in terms of rain chances. Daily afternoon pops should be 30-40% each day the local area will be under a shear zone between Bermuda ridge that moves into the western Atlantic and a trough moving east across the northern half of the country. MEFFER AVIATION... VFR conditions are expected to dominate for the rest of this afternoon through Saturday morning. The only exceptions will be briefly lower conditions due isolated SHRA/TSRA, affecting KMSY, KNEW, KASD, KGPT and KHUM mainly through 23z. There may also be another round of MVFR to IFR conditions due to BR/light fog at KMCB late tonight/early Saturday morning. MARINE... Bermuda surface ridge extending across the Gulf of Mexico will keep flow onshore throughout the forecast period. The local coastal waters will continue to see the typical diurnal wind increase/decrease as nocturnal winds rise to 10 to 15 knots which will carry over into the morning hours and then drop down the rest of the day closer to 10 knots or slightly less. This should continue into the weekend. Nocturnal sh/ts will also develop during the late night and early morning hours through the next several days. Winds will begin to shift to a more SE direction by Sunday as the ridge shifts northward. DECISION SUPPORT... DSS code: Green. Deployed: None. Activation: None. Activities: None. Decision Support Services (DSS) Code Legend Green = No weather impacts that require action. Blue = Long-fused watch, warning, or advisory in effect or high visibility event. Yellow = Heightened impacts with short-fused watch, warning or advisory issuances; radar support. Orange = High Impacts; Slight to Moderate risk severe; nearby tropical events; HazMat or other large episodes. Red = Full engagement for Moderate risk of severe and/or direct tropical threats; Events of National Significance. && .PRELIMINARY POINT TEMPS/POPS... MCB 76 93 74 94 / 10 20 20 50 BTR 77 94 76 94 / 10 20 10 50 ASD 79 94 76 93 / 10 40 20 50 MSY 81 94 79 92 / 10 40 10 50 GPT 80 92 76 91 / 10 30 20 40 PQL 78 93 76 94 / 10 30 20 40 && .LIX Watches/Warnings/Advisories... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion...UPDATED National Weather Service Shreveport LA 650 PM CDT FRI JUL 8 2016 .AVIATION... VFR conditions will continue through much of the 09/00Z TAF period. The cu field will diminish shortly after sunset...with the cirrus shield expected to gradually increase from the NW...associated with sct strong convection over NW TX/Cntrl OK. May see low MVFR/IFR cigs develop just before daybreak Saturday over portions of the Wrn sections of E TX...with patchy FG/LIFR cigs developing near LFK. However...these cigs should be more scarce than what has developed each morning this week. Any low cigs that develop will scatter out by 15-16Z...with a sct cu field developing by midday elsewhere beneath cirrus cigs. Sct convection is expected to develop Saturday afternoon over Cntrl AR and may backbuild SW into the NE sections of SW AR...but should remain NNE of the TXK/ELD terminals. S winds 4-8kts tonight will become SSW after 15Z. /15/ && .PREV DISCUSSION... /issued 337 PM CDT FRI JUL 8 2016/ DISCUSSION... The upper air ridge across the ARKLATEX late this afternoon is gradually breaking down/shifting East away from the region, courtesy of upper air troughiness draped from the Great Lakes Region to across the Central Plains. Although the ridge is doing a decent job at keeping storm chances at bay, as shown by sea- breeze convection having been confined to Southern LA, but can not rule out a few showers making it to central LA later this aftn. Furthermore, will also need to pay close attention to Eastward propagating thunderstorm activity that have been plaguing portions of the Central Plains and mid-Mississippi Valley most of the day, aided by a nearby cold front. If an outflow boundary shift South towards the region, it could serve as a focus for CI later this aftn/early evening as hinted at by the HRRR solution. Tonight appears to be the slightly better opportunity for precipitation especially for the Northern zones, as the Southern periphery of the UA trough swings across the area and provide a bit of large scale ascent. Otherwise, slightly gusty South to Southwest winds have prompted temps to warm into the 90s or 2 or so degrees above normal. Lack of beneficial rainfall within the last few weeks and a downslope wind component thus keeping temps hot, will lead to soils continuing its drying effects. This is especially seen across the Western zones as dewpoints are a few degrees lower than this time yesterday afternoon. It is still going to take some time for significant drying to take place but the process is underway. As the upper air ridge shifts to the Southeast CONUS this weekend, Northwest flow aloft will prevail and embedded disturbances within the flow aloft along with a slowly Southward sagging cold front, will lead to the return of precipitation chances, particularly across Northern and Eastern zones. The ridge is anticipated to make a return early next week thus encouraging the retreat of the nearby frontal boundary and hence diminishing chances for significant widespread precipitation. The only precipitation potential will be diurnally driven sea-breeze convection mid-late week as hinted at by long term solutions. Temperatures will remain at/above normal throughout the extended forecast though humidities will ever so slightly be lowering. So the question begs as to whether or not to extend the Heat Advisory beyond today. Highest dewpoints were noted across the Eastern zones late this aftn, coinciding with the highest heat indices and where a portion of the Heat Advisory is currently in effect. Tomorrow, temperatures may be a few degrees cooler than today /albeit still warm/ given the exiting ua ridge corresponding to lowering 500 mb height fields. The soils will continue to dry and so will the humidity. Will therefore hold off on extending the Heat Advisory attm, but can not rule out heat indices still hovering around/slightly above 100 degrees across the Eastern zones. AVIATION... VFR conditions will continue to dominate the aviation forecast over the next 24 hrs. Some early morning low clouds ceilings may be observed in Deep East Texas...but elsewhere they will be scattered. Widely scattered shra/tsra activity may affect our Arkansas terminals tomorrow afternoon...but at this time the chances are too low to mention in the taf. Southerly winds will continue to prevail through the period. /11/ && .PRELIMINARY POINT TEMPS/POPS... SHV 77 95 77 96 / 10 10 10 20 MLU 77 94 76 94 / 10 30 20 30 DEQ 76 93 75 93 / 20 30 20 30 TXK 77 95 77 94 / 20 20 20 30 ELD 77 94 76 94 / 20 30 20 30 TYR 77 96 77 96 / 10 10 10 10 GGG 77 96 77 96 / 10 10 10 10 LFK 77 95 77 96 / 0 20 0 10 && .SHV Watches/Warnings/Advisories... AR...Heat Advisory until 7 PM CDT this evening for ARZ072-073. LA...Heat Advisory until 7 PM CDT this evening for LAZ001>006-010>014- 017>022. OK...None. TX...Heat Advisory until 7 PM CDT this evening for TXZ151>153-165>167. && $$ 15