Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/06/19

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
629 PM MDT Mon Aug 5 2019 .AVIATION... 00Z TAF CYCLE Isolated convection will continue through the evening hours, mainly along and east of the central mountain chain. High clouds will increase from the south overnight as moisture surges up from Sonora. An uptick in thunderstorm coverage is expected for all terminals Tuesday afternoon and evening with the exception of KROW. 33 && .PREV DISCUSSION...452 PM MDT Mon Aug 5 2019... .UPDATE... Quick update to PoPs for this evening, dropping overall chances as mid-level dry air wrapping into northwestern NM and subsidence beneath the upper high has put a damper on storm development over the northwestern high terrain. Also updated to take into account lingering showers/storms along a bdry that has been picked up by the RAP pushing into into east-central NM tonight. 24/RJH && .PREV DISCUSSION...252 PM MDT Mon Aug 5 2019... .SYNOPSIS... An active week of afternoon thunderstorms will continue for western and northern New Mexico after a relative down day today and this evening. The best storm coverage for Tuesday will focus over/along the western high terrain, shifting to the northern mountains Wednesday. Some storms Wednesday over the northern mountains will work their way into the northeastern plains by the evening. The upper high jogs into Texas to end the week allowing for a better tap of monsoon moisture into western and central New Mexico favoring more afternoon storms for western, central, and northern New Mexico. The southeastern plains will be relatively quiet in terms of storm activity to end the week. Temperatures will remain near to above normal through the forecast period with Tuesday and Wednesday likely seeing a couple of 100s across the eastern plains. && .DISCUSSION... Tonight...Mid-level water vapor is showing some drier mid-level air wrapping around the northwestern periphery of the high into northwestern NM today, putting a damper on any thunderstorm development there so far. Convection is developing over the southwest mountains and central mountain chain with storm motions generally toward the southeast/east. Lingering storms late into the overnight period will favor south-central portions of the CWA. Tuesday/Wednesday...Models continue to be in good agreement with nudging the upper high center back over NM with a weak perturbation along the western side of the high on Tue. This will help increase storm coverage over the western high terrain and continental divide. Storm coverage across the east will remain relatively low. Storm motions, with little to no steering flow, will return to be slow and erratic. Locally heavy rainfall and the threat for flash flooding will return with any slow moving efficient rain producer across the west Tuesday. The upper high center moves little Wednesday with the aforementioned perturbation rotation around the high into the northern mountains and into CO. Thus the highest coverage of storms will shift to the northern mountains with storm motions increasing a bit toward the east into northeastern NM Wednesday evening. Late Week/Weekend...PWATs will remain 1-2 std deviations above climatological normals ranging from 1.00"-1.20" at KABQ. Meanwhile, both the GFS and ECMWF have continued to show an eastward progression of the upper high into TX to end the week. This will allow a more typical monsoon plume of moisture to advect northward into western and central NM during this time keeping increased thunderstorm activity going each day there. Storm motions also increase a bit from S to N across the west, and more SW to NE or W to E over northern NM. Daily trends will continue to favor the western and northern high terrain for the first round of afternoon thunderstorms with lower valley locations of western and central NM as well as the northeastern plains likely receiving the second round late in the day and evening. Unfortunately this pattern doesn`t favor robust thunderstorm activity for southeastern portions of the state. Looking even longer, the GFS is hinting at the upper high flattening and more of a zonal flow pattern setting up over the northern CONUS with drier air pushing into western NM for next week or mid-August. 24/RJH && .FIRE WEATHER... The high moisture content of the atmosphere remains intact as high pressure aloft continues to orbit NM, yielding a typical monsoon pattern for early August. This week, hot and seasonable temperatures will be complemented by afternoon humidity typically falling to 25 to 45 percent, but good to excellent humidity recovery is expected during the overnight periods. Otherwise the main fire weather concerns will be dependent on scattered to numerous showers and thunderstorms that will initiate over the southwestern to west central and northern mountains of the state during the afternoons. Storms will attempt to fill into adjacent lower elevations and valleys each evening, but very low rain chances will persist for far northwestern and far east central New Mexico. Storms will be slow- moving and capable of producing heavy downpours with burn scar flooding and gusty outflow winds threatening, as well as the occasional new lightning ignition from strikes that occur away from main precipitation cores. 52 && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$ 24
Area Forecast Discussion
National Weather Service Denver/Boulder CO
916 PM MDT Mon Aug 5 2019 .UPDATE... Issued at 847 PM MDT Mon Aug 5 2019 A few showers and weak storms are ongoing over the northeastern plains. These will continue through about midnight before dissipating. In addition, a few showers are moving over southern Park County this evening but will exit our CWA shortly. With stable air elsewhere, POPs were lowered below 10 percent for the rest of the night as dry conditions will prevail. Otherwise, the forecast is on track for a quiet night. && .SHORT TERM...(This evening through Tuesday) Issued at 207 PM MDT Mon Aug 5 2019 Convection has fired across the foothills this afternoon and has struggled to move off the higher terrain so far, because it is encountering significantly drier air compared to yesterday. Dewpoints have mixed out to 50 degrees south of the Cheyenne Ridge. Dewpoints are still in the low 60s across northeast Colorado, east of an Akron to Sterling line. Instability to the west of the area of higher dewpoints is meager and should support just widely scattered showers and thunderstorms into the evening hours with gusty winds and not much rainfall. Convection is a bit more robust across Larimer County and we still think storms will expand in coverage across the Cheyenne Ridge and move southeast across the northeast plains. PoPs are accordingly highest there. The best chances this evening continue to be across Larimer, Weld, Morgan, Logan and Logan Counties. Can`t rule out a few storms across Park County and the Palmer Divide but recent GOES-16 data suggest those areas are not as unstable as along the Cheyenne Ridge. Impacts from storms this evening along the Cheyenne Ridge would be gusty winds 40 mph or higher, brief heavy rain, and some lightning. If any storms make it to the far northeast corner there could be even stronger winds and marginally severe hail. With no significant forcing upstream, most areas will clear after midnight and precipitation chances drop quickly, but latest runs of the HRRR have an MCS moving southeast across Phillips/Sedgwick Counties sometime between 3-6 AM. Instability and shear would favor an MCS surviving the trek, so have introduced PoPs during that time period. Strong winds, lightning, and brief heavy rain would ensue if that occurs. Otherwise expect lows in the 60s plains and 40s in the high country with mostly clear skies by sunrise. On Tuesday the persistent ridge remains over the Four Corners, and the juicy monsoonal moisture is locked up to the south of Colorado. Storm chances Tuesday afternoon should be isolated. PW values remain on the low side as well, in the 0.5" range in the mountains and 0.75-1.0" across the plains. Hard to pin down any more favored locations for convection, but broad brush 15-30% for northern quarter of our area plus the plains. Closer to the moisture, have included a bit higher chance for Park County, the I-70 corridor, and points south like the Palmer Divide. 700 mb temps warm a few degC on Tuesday, to around +17 degC, and with expected reduced cloud cover compared to previous days, low to mid 90s look attainable for the plains for highs, with 70s to low 80s in the high country. .LONG TERM...(Tuesday night through Monday) Issued at 207 PM MDT Mon Aug 5 2019 For Tuesday night into Wednesday, isolated storms will propagate across the eastern plains into the evening hours. With drying in the lower levels storms will mainly produce gusty winds with some rain. The high pressure ridge that has been dominating our weather pattern over the last few weeks will move southeastward into New Mexico during the day Wednesday and then into Texas by Thursday. This will allow for embedded shortwaves to impact Colorado both days. For Wednesday, the shortwave is currently projected to move into NE Colorado by the afternoon helping to provide lift for storms that afternoon. At the surface, a deepening lee side low will move southeastward pulling winds from the northeast helping to increase moisture along the foothills and adjacent plains. Scattered storms will develop over the mountains and move onto the plains into the evening hours. CAPE values will be decent with values upwards of 2000 j/kg east of a Sterling to Akron line with deep shear values from 40 to 45 kts. This would support strong to a few isolated severe storms across the NE plains with large hail and damaging winds as the primary hazards. Wednesday will be the last above 90 day for the week with temperatures dropping into the 80s for the remainder of the long term period. On Thursday, surface high pressure will strengthen across the area with continued easterly flow. This will help to maintain enhanced upslope flow along the base of the foothills and moisture on the plains. Model cross-sections show some cloud cover late Wednesday into Thursday morning with the enhanced moisture along the foothills and eastern plains. This cloud cover will hinder some solar insolation and could delay mixing. Once the clouds are able to dissipate, instability in the form of CAPE values from 1000 to 1500 j/kg and shear values from 30 to 35 knots will allow for isolated to scattered storms Thursday late afternoon and into the evening hours. Gusty winds and hail along with brief moderate to heavy rain will be the main threats. For Friday and into the weekend, another shortwave will move through the region Friday afternoon. This will aid in the development of storms for Friday afternoon. With precipitable water values well over an inch across the eastern plains, the biggest threats from these storms will be heavy rain, hail and gusty winds. For the weekend, it appears the upper ridge will stay over the Texas region keeping moisture levels on the moderate end over eastern Colorado with some drying across the West. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 847 PM MDT Mon Aug 5 2019 Two boundaries are colliding around DEN this evening with one coming from the southwest and the other from the northeast. The airmass behind each boundary is nearly similar so there is low confidence on which one will win out. Winds may end up being variable for a short time but south or southwest winds should eventually prevail. Drainage flow will persist into the morning hours before westerly winds increase shortly after sunrise. Winds will be light throughout much of the afternoon tomorrow. A stray shower or storm cannot be ruled out but coverage will be low enough to not mention storms in the TAFs. The only affects on the airports would be gusty outflow winds. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Danielson SHORT TERM...Schlatter LONG TERM...Bowen AVIATION...Danielson
Area Forecast Discussion
National Weather Service Columbia SC
1013 PM EDT Mon Aug 5 2019 .SYNOPSIS... Scattered showers and thunderstorms are expected through Wednesday as a surface and upper trough remain over the forecast area. Typical summer weather is foreseen for the remainder of the week with scattered diurnal showers and thunderstorms. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Water vapor imagery shows drier air aloft and a weak shortwave pushing into the forecast area from the west. The few isolated showers and thunderstorms will linger over the next few hours supported by the shortwave and pockets of weak elevated instability. We expect convective activity to diminish shortly after midnight with the shortwave pushing to the east. Light wind and clearing skies will lead to strong radiational cooling and may allow patchy fog to develop around sunrise. Lows overnight will mainly be in the lower 70s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... The upper-level ridge will flatten and there could even be some weak shortwave ridging building in on Tuesday. Meanwhile at the surface, a weak/diffuse front will be stalled over the area in the morning, but should shift toward the coast as the day progresses. With the front shifting to the east and less upper level support than the past few days, convection should be less widespread. However, there will still be plenty of moisture around with precipitable water values of 1.5 to 1.75 inches and moderate instability in place, so will continue to show isolated showers and thunderstorms in the afternoon and evening, with scattered coverage across the eastern Midlands closer to the front. Early morning areas of fog then stratus into midday could keep temperatures down a bit, with highs around 90. Lows Tuesday night should be in the lower 70s. The upper trough should amplify a bit on Wednesday, with a fairly moist southerly flow prevailing at the surface. No significant forcing mechanisms will be present, but think the pattern could support scattered showers and thunderstorms in the evening. The trough axis and associated weak front at the surface should pass through Wednesday night. Temperatures will be on a warming trend, with highs in the lower to mid 90s and nighttime lows in the lower to mid 70s. The axis of the upper trough and associated surface front will shift to the east on Thursday, resulting in a northwest flow. Significantly drier air will advect into the region as a result, with precipitable water values dropping to 1.25 inches or less. Most areas will be rain-free, but the forecast does indicate the potential for an isolated thunderstorm across the lower CSRA and eastern Midlands in closer proximity to the front and greater moisture near the coast. Highs will be in the mid 90s most places with lows once again in the lower to mid 70s. && .LONG TERM /FRIDAY THROUGH MONDAY/... The long wave trough will prevail over the western Atlantic Friday through the weekend, maintaining a drier northwest flow aloft across the region. While this drier airmass will generally curtail shower and thunderstorm development, lower confidence in the forecast as models show some disagreement on timing/placement of shortwave disturbances moving through within the northwest flow. For now will lean closer to climatology with mainly diurnal isolated to scattered showers and thunderstorms, with greater chances over the weekend than on Friday. Friday should be the warmest day of the week with highs in the mid to upper 90s, with only slightly cooler temperatures expected over the weekend. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... VFR conditions expected to start the forecast period but restrictions in fog/stratus expected to develop during the predawn hours. Upper level trough axis continues to move through the area overnight and still some lingering convection around the region. Abundant low level moisture and some expecting drying in the mid level overnight and not much of a low level jet should support IFR fog/stratus later tonight. MOS guidance is indicating visibilities and ceilings dropping around 09z or so and this is supported by the latest runs of the HRRR so have made little change to the previous forecast with restrictions beginning at 07z AGS/OGB and around 09z elsewhere. Winds will be light and variable to calm overnight then pick up from the southwest to south after 15z Tuesday with VFR conditions returning as cigs lift into a cumulus field. EXTENDED AVIATION OUTLOOK...Scattered mainly diurnal thunderstorms as well as late night and early morning stratus and fog will be possible, mainly through Wednesday. Drier conditions then expected through late week. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Cheyenne WY
550 PM MDT Mon Aug 5 2019 .SHORT TERM...(This evening through Wednesday) Issued at 210 PM MDT Mon Aug 5 2019 Forecast concerns in the short term deal with severe weather chances. Currently...Four Corners High still in place over said area this afternoon. 12Z Grand Junction sounding showing PWATS slightly dropping a bit this morning...but still right around an inch. At the surface...cold front that was over northern Wyoming this now being analyzed from just north of south of Casper to near Cokeville in extreme western Wyoming. Modest low level moisture increases observed behind the front with dewpoints in the upper 50s. South of the front...dewpoints in the mid 40s are common. Latest SPC Mesoanalysis showing surface based CAPES in the mid 2000 J/KG across the Panhandle with 1000/1500 J?KG over southeast Wyoming. Radar starting to show initiating across southern Albany County and extreme southern Laramie Range at 144PM this afternoon. Storm motions have been to the southeast. For this afternoon and tonight...Appears the HRRR simulated radar is handling current storms the best and generally followed its guidance through the period. Storms really begin developing after 22Z and take on a more easterly movement off the Laramie Range. HRRR showing possibility of discrete supercells developing and has one near Cheyenne...with another near Wheatland. NAM MU CAPEs near 2000 J/KG after 21Z on both the NAM and RAP. Better shear today...on the order of 35-45kts should help in severe thunderstorm development. HRRR has been very consistent on developing a possible squall line this evening up near Converse County with line bowing out over Niobrara County and the northern Panhandle late this evening. Would anticipate the evening shift issuing warning through late evening and possibly beyond as the line shifts to the southeast into the central and possibly the southern Panhandle after 08Z. A slightly drier day with less convection expected Tuesday as moisture shifts east into Nebraska. Still may see a couple severe thunderstorms in the Panhandle Tuesday afternoon. SPC`s Marginal Risk area looks good for the Panhandle. .LONG TERM...(Wednesday night through Monday) Issued at 210 PM MDT Mon Aug 5 2019 Thursday...Looks like a decent setup for scattered to numerous showers and scattered thunderstorms in the afternoon and evening with adequate low and mid level moisture, upslope low level southeast winds and a shortwave trough aloft passing overhead around peak heating. Temperatures will be cooler than Wednesday with increased cloud cover and a greater coverage of showers and thunderstorms. Friday...With some decrease in low and mid level moisture, will see a general decrease in shower and thunderstorm coverage. Saturday...Ridging develops aloft, though with enough low and mid level moisture, will again see isolated to scattered afternoon and evening shower and thunderstorm coverage. Sunday...Warmer temperatures aloft will help inhibit thunderstorm development, thus the coverage of showers and thunderstorms will be more isolated. Monday...Somewhat drier air moves in at the low and mid levels, making for a mostly dry day with perhaps an isolated thunderstorm or two over and near the southern Laramie Range. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) Issued at 542 PM MDT Mon Aug 5 2019 Wyoming TAFS...Thunderstorms in the vicinity to occasional thunderstorms at KCYS from 00Z to 03Z producing wind gusts to 25 knots and MVFR visibilities. KLAR and KRWL will see VFR conditions this evening and overnight with wind gusts to 10 knots until 12Z. Nebraska TAFS...Thunderstorms in the vicinity from 03Z to 05Z in the Panhandle for airport sites. This trend will continue to quiet down in the early night hours. KCDR and KAIA have the chance for winds to die down and fog to develop between 07Z-09Z. Ceilings will lower down accordingly. Expect skies to clear out by daybreak. && .FIRE WEATHER... Issued at 210 PM MDT Mon Aug 5 2019 Minor fire weather concerns for Tuesday as monsoonal moisture shifts east out of Carbon County. Could see afternoon humidity falling to a little below 15 percent across Carbon County Tuesday. Fortunately...winds are expected to be fire weather should be minimal Tuesday. Increasing moisture again Wednesday into the end of the week as chances for wetting rains begin to increase. Widespread showers and thunderstorms likely Thursday. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...GCC LONG TERM...RUBIN AVIATION...BMW FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Des Moines IA
637 PM CDT Mon Aug 5 2019 .DISCUSSION.../Tonight through Monday/ Issued at 337 PM CDT Mon Aug 5 2019 Synoptic Overview: Mid to upper-level flow over the upper Midwest will remain northwesterly for much of this week, sandwiched between troughing over the mid Atlantic and east coast with amplified ridging over the western CONUS. A few short-wave troughs will slip through the mid-level flow brining periodic rain shower and thunderstorm chances this week. Temperatures to remain near seasonable in this large- scale pattern. Today and Tonight: Severe weather potential will remain in place late this afternoon through late this evening, especially across the north-central and northeastern parts of the CWA where SPC SWODY1 enhanced risk is. Slight Risk for severe weather extends to the southern and southeastern portions of the CWA. Best moisture transport remains across north-central and northeastern Iowa this afternoon ahead of short-wave trough and associated cold front across the eastern Dakota`s and Minnesota. GOES-16 visible imagery has been showing decent clearing after this morning`s weak convection across northern Iowa. CAMs continue to depict axis of greatest instability from EST up through MSP, with SBCAPE in excess of 4000 J/kg. HREF mean SBCAPE across the rest of the north and northeast CWA depicts SBCAPE between 2500 and 3500 J/kg. In conjunction with thermodynamic instability, HRRR and RAP soundings also depicting healthy low-level lapse rates near 8.5 K/km and decent lapse rates through the mid- levels. Thus anticipate healthy updrafts early on which may be strong enough to present large hail threat. Effective bulk-shear 25- 30 knots should allow for decent organization of thunderstorms early this evening, especially north of U.S. Hwy. 30. Low-level shear is not overly impressive, a large factor into the limited tornado threat with storms tonight. Dewpoint depressions values will be quite high prior to the onset of convection. Combine this with considerable low-level lapse rates, expect the potential for damaging wind gusts with thunderstorms, with a few downbursts favorable in this environment. There is still some discrepancy in CAM runs this afternoon regarding the convective mode. ESRL HRRR and NMM have attempted to develop bow-like features later this evening into the overnight hours, which would align with the threat for damaging wind gusts. Through the 16z runs, the HRRR was not nearly as excited about bowing features along the cold front this evening. However, CAMs are in decent agreement in highlighting areas north of U.S. Highway 30 for active severe weather. The uncertainty with the southward extent of severe weather this evening lies in how well any cold-pool is maintained within the thunderstorm complex. If the shear environment ahead of the boundary remains in place, there may be enough balance to continue the severe weather threat as it propagates southward. However, if this is not realized, it may just lead to a widespread moderate rain showers south of U.S. Highway 30 to the Missouri state line. The only considerable change to the forecast for thunderstorms tonight has been to delay the onset of initiation a few hours. For Iowa, the bulk of the activity is not expected until after 00 UTC. However a cumulus field is producing precipitation as of 20z in northwestern Iowa. Given a favorable environment, there is potential for this initial convection to reach severe limits, thus have issued Severe Thunderstorm Watch 554 for counties north of U.S. Highway 30 until 04 UTC tonight. With respect to rainfall totals, thunderstorms will be rather efficient this evening with PWATs around 1.75 inches. The flow should be strong enough where the storms will progress at a decent pace across the CWA. Looking at a widespread half to three-quarters of an inch of rain, with up to 1.25 inches locally possible. With rather dry antecedent conditions, not all too concerned with flooding or flash flooding at this time. However, if the rainfall begins to outperform the forecast, this may need to be adjusted. For now, will hold off on any flooding headlines. Extended Forecast: Conditions dry out by Tuesday afternoon under northwesterly flow with no short-wave perturbations in sight at this time as surface high pressure slides in underneath. Next short-wave feature swings a vort max through Iowa Wednesday morning brining rain showers primarily to central and western Iowa during the morning and afternoon hours. Mid to upper-level flow becomes relatively benign toward the middle end of the work week through Sunday. Temperatures in this pattern will remain seasonable in the mid to upper 80s for the majority of this week. Substantial precipitation chances then return to the forecast Sunday Night into Monday as another short- wave trough works through the northwesterly flow over the upper- && .AVIATION.../For the 00Z TAFS through 00Z Tuesday evening/ Issued at 637 PM CDT Mon Aug 5 2019 Surface front will slide through the state overnight with scattered thunderstorms in vicinity of the boundary. Conditions will be mostly VFR, but MVFR to IFR in and around thunderstorms. Some areas of MVFR to IFR fog will also be possible around daybreak with winds becoming light and variable along with residual moisture from this evenings rainfall in surface layer. Mainly VFR conditions on Tuesday with north to northwest winds. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DISCUSSION...Krull AVIATION...Cogil
Area Forecast Discussion
National Weather Service Indianapolis IN
1152 PM EDT Mon Aug 5 2019 .UPDATE... The AVIATION Section has been updated below. && .SYNOPSIS... Issued at 238 PM EDT Mon Aug 5 2019 An isolated shower or storm will be possible this evening as high pressure south of Central Indiana continues to drift southeast. Most areas will remain just partly cloudy this evening. Better chances for rain will arrive in the area on Tuesday as a cold front arrives from the upper midwest. Showers and storms will be possible on Tuesday as this front pushes across the state through Tuesday. More chances for showers and storms will persist on Wednesday through Thursday night as a few weaker fronts push across Indiana. Dry weather looks to return for the weekend as high pressure once again builds across Indiana. && .NEAR TERM /Tonight/... Issued at 238 PM EDT Mon Aug 5 2019 Surface analysis early this afternoon shows high pressure in place across SE Missouri...stretching northeast through the Ohio Valley. Low pressure was found over Ontario...with a cold front stretching southwest across Minnesota to the plains states. Dew points were a bit higher the middle more of a westerly surface flow has developed. GOES16 shows some diurnal cu building across Central Indiana...and radar has hinted at a few isolated showers trying to develop. Water Vapor imagery shows NW flow in place across the region...flowing from a ridge axis across the Rockies. A short wave was found from Minnesota to Nebraska...pushing ESE. National Radar Mosaic shows a few showers or storms entering the western Great Lakes. HRRR shows a few scattered showers developing late this afternoon across Central Indiana and given the latest radar and satellite trends...this seems reasonable during our peak heating hours. Forecast soundings and Time heights then dry out this evening as heating and instability is lost...leading to another mainly clear night. Thus will continue to keep some chances in late this afternoon and evening. The next short wave is expected to push into the area overnight and forecast soundings hint at some high saturation arriving ahead of this system. Thus will expect some increasing clouds late overnight. Given the Warm air advection and cloud cover ahead of the approaching system...will trend lows at or above the NBM. && .SHORT TERM /Tuesday through Thursday/... Issued at 238 PM EDT Mon Aug 5 2019 GFS and NAM both agree a short wave will push into Indiana on Tuesday. NAM keeps the best forcing to the north while the GFS bring significant forcing across the entire forecast area. Thus Furthermore...both models bring the associated cold front across Indiana during the best moisture should be ahead of the lower level forcing. Thus overall feel best chances during the day will be across the northern parts of the forecast area...trending to lesser pops across the south. Given the expected clouds and precip will trend high at or below the NBM. NW flow continues to persist on Tuesday night through Thursday...with a second...albeit weaker short wave passing across the area on Wednesday. Lower level flow remains cyclonic on Wednesday morning before a surface ridge finally builds in across the area from the northwest on Wednesday afternoon. Little to no upper support appears to arrive on Thursday. Thus will keep some pops in place on Tuesday night and Wednesday morning as upper support remains in play...but try to trend toward a dry forecast by Wednesday night and Thursday as Ridging and NW flow resumes. && .LONG TERM /Thursday night through Monday/... Issued at 247 PM EDT Mon Aug 5 2019 The long term will start out with lingering chances for showers and thunderstorms through Friday as a surface front slowly sinks south of central Indiana with northwest flow aloft. High pressure will build in from the northwest on Friday and by Friday night should shove the front down to the south and allow dry conditions to move into central Indiana. Temperatures will drop to near normal early in the extended but then begin to climb as high pressure builds over the area through the weekend and into next week. && .AVIATION /Discussion for the 06/06Z TAF Issuance/... Issued at 1147 PM EDT Mon Aug 5 2019 A cold front will bring rain showers to central Indiana and are progged to affect TAF sites by Tuesday afternoon. Conditions will generally be at VFR levels for most of the TAF period outside of any abrupt deterioration in visibilities during possible rain showers. The only caveat will be when MVFR becomes prevailing at KIND late in the TAF period. Meanwhile, winds will generally be southwesterly at 5 to 10 kts. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS...Puma NEAR TERM...Puma SHORT TERM...Puma LONG TERM....CP AVIATION...TDUD
Area Forecast Discussion
National Weather Service Pueblo CO
321 PM MDT Mon Aug 5 2019 .SHORT TERM...(This evening through Tuesday) Issued at 321 PM MDT Mon Aug 5 2019 Drier air aloft has worked its way around the northwest side of the upper ridge behind this mornings shortwave. Meanwhile, deeper moisture continues to reside across the 4 corners region within closer proximity to the monsoon moisture fetch around the upper high centered over AZ. Still plenty of moisture over southern CO with most areas in the 90-130% of normal range (highest values across the east). Meanwhile weak surface front has pushed through southeast CO with winds expected to gain a more northeasterly component into this evening. Thunderstorms have fired over the mountains and a few will drift off into the adjacent plains late this afternoon through evening. Satellite imagery also showing some convergence across Baca county along stalled frontal boundary which may also help focus thunderstorm development this evening as a few HRRR runs have indicated. Models differ with how moist low levels will stay this afternoon across the eastern plains with GFS and HRRR showing some drying and limited CAPE...while NAM keeps dew points well into the 50s and CAPE values potentially up above 1500 J/kg across the far eastern plains. Reality will probably end up somewhere in between but have leaned towards the wetter solution based on latest dew point trends. Main risks will be locally heavy rainfall, lightning and gusty erratic winds. Small hail will also be possible with the locally stronger storms, but with weak wind shear today, the threat for severe thunderstorms looks low. Burn scars will need to be monitored closely this evening for a flash flood risk given relatively high precipitable waters and potential for heavy rainfall. However, threat today looks pretty par for the course during the monsoon season with nothing to sink our teeth into as to which burn scars will be hit and which will not. Weak impulse energy may help maintain thunderstorms across the southeast mountains through the evening hours and will maintain some isolated pops past midnight. Low level flow swings around from the southeast across the plains maintaining 50 dew points across the lower elevations on Tuesday. Meanwhile, moisture plume aloft will start to spread back northward into more of the western mountains. Really not a lot of change to the forecast for Tuesday with another round of scattered thunderstorms expected in the afternoon across the mountains, spreading eastward during the late afternoon and evening along surface trof axis. With weak shear, and high precipitable waters, heavy rainfall carrying a localized flash flood threat will be the primary concern. -KT .LONG TERM...(Tuesday night through Monday) Issued at 321 PM MDT Mon Aug 5 2019 Tuesday night-Wednesday night...Modest northwest flow aloft across the region on Tuesday becomes more westerly through the day on Wednesday, as upper high pressure across the Desert Southwest is slowly shunted south and east by a broad upper trough translating across the Northern Tier. This will allow for atmospheric moisture to increase across the region, especially along and west of the ContDvd on Wednesday. This, along with a weak front expected to back into eastern Colorado through the afternoon, will allow for increased coverage of afternoon showers and storms across the area on Wednesday, especially over the higher terrain. Increased low level moisture behind the weak front, with a slight increase in shear, could produce a few stronger storms across the far eastern Plains late Wednesday afternoon and evening. Temperatures on Wednesday look to be around to slightly above seasonal levels, warmest across the eastern Plains. Thursday-Friday...Models in decent agreement of the "monsoonal moisture" tap moving across the region within weak southwest flow aloft, as upper level high pressure continues to be positioned south and east of the Rockies. This, combined strong solar heating and moist low level upslope across the Plains, will bring better coverage of afternoon and evening storms across all of south Central and southeast Colorado, with the best coverage over and near the higher terrain through the afternoon, with storms moving east across the Plains through the late afternoon and evening. Weak westerly steering flow aloft will allow for locally heavy rainfall and the potential for flash flooding, especially for the newer burn areas of the Spring, Junkins and Hayden Pass scars. With the better chances and coverage of storms, highs through this period look to be at to slightly below seasonal levels. Saturday-Monday...Upper level high pressure is progged to slowly retrograde west through the weekend, with drier air within the more westerly flow aloft expected to slowly decrease the coverage of afternoon and evening storms by early next week. Best storm coverage over the weekend will be over and near the higher terrain, with the continued weak steering flow leading to locally heavy rainfall and the potential for flash flooding through the weekend. Temperatures look to be around seasonal levels through the period. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 321 PM MDT Mon Aug 5 2019 VFR conditions expected at the terminals with erratic gusty outflow winds up to 40 kts possible near VCTS. All three terminals will carry some risk for -TSRA through the evening, though primary impact will be shifting winds from thunderstorm outflows. VCTS will persist the longest for KPUB and KALS but all three terminals should see diminishing probabilities after 06z with VFR conditions expected overnight. Northerly winds today behind the cold front will transition back to south to southeasterly for Tuesday with thunderstorms expected to develop over the mountains again during the afternoon. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KT LONG TERM...MW AVIATION...KT
Area Forecast Discussion
National Weather Service San Diego CA
153 PM PDT Mon Aug 5 2019 .SYNOPSIS... Moisture aloft will move into Southern California overnight through Tuesday around the western periphery of an upper level ridge over Arizona. This could result in a few lightning flashes and strikes over San Diego and portions of Riverside County overnight through Tuesday morning. Then, a few thunderstorms could develop over the mountains on Tuesday afternoon. A weak trough of low pressure off the coast will spread cooling inland through midweek. Some slight additional cooling is possible for Friday and Saturday as a low pressure system moves inland into the Pacific Northwest. Warming will resume around Sunday as a trough of low pressure near the West Coast weakens. Night and morning coastal slow clouds will extend into portions of the western valleys at times. && .DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO COUNTIES... .Highlights... * Slight chance of dry lighting San Diego and southern Riverside Counties after midnight tonight-Tuesday morning * Thunderstorms possible over the mountains Tuesday afternoon Some changes to the forecast this afternoon. A complex of thunderstorms over the northern Gulf of California will continue to spread west-northwest while dissipating. However, moisture from this complex will spread north of the international border tonight, especially after midnight. The moisture will be confined above 12,000 feet with very dry air remaining below. HRRR and WRF do show some elevated CAPE spreading in from the south after midnight. This leads to concern for dry lightning potential overnight-Tuesday morning. For this reason, added in a slight chance of dry lightning for San Diego County into southern portions of Riverside County after midnight tonight through Tuesday morning. Low confidence, but enough concern to mention the potential. The peak of the moisture, PW near 1.40 inches, will occur Tuesday afternoon and this could lead to a few thunderstorms developing over the mountains Tuesday afternoon. The big limiting factor for tstorm development Tuesday will be a mid/high level cloud shield, but hi-res models do show the possibility of some rainfall occurring over the mountains, albeit light. The heat is really on this afternoon over the lower deserts. It`s looking like temps could reach 120 at a few locales. The forecast was updated earlier to reflect this higher trend. The good news is cloudiness spreading in from the south tonight-Tuesday will lead to a reduction in temps tomorrow and for the middle to latter part of the week, an upper level trough digging in from the northwest will lead to lowering heights/thermal fields, keeping excessive heat at bay, so today is the last day of the brutal heat there. Heat headlines will expire at 8 PM this evening. && .LONG TERM Thursday through Sunday (From previous discussion)... Minor changes are expected for Thursday. Friday and Saturday may cool slightly as a low pressure system moves inland into the Pacific Northwest. Warming will resume on Sunday as a trough of low pressure near the West Coast weakens. Night and morning coastal low clouds will extend inland into portions of the western valleys at times. && .FIRE WEATHER... * Slight chance of dry lightning after midnight tonight-Tuesday morning Moisture aloft will be spreading in from the south tonight with the potential of a few lightning flashes and strikes after midnight over San Diego and southern Riverside Counties. Low confidence on this, but the potential is there. This would not be a widespread lightning event with only a few strikes to occur, if at all. There is a better chance of lightning over the mountains on Tuesday afternoon, although still low probabilities and we expect those to be associated with some light rainfall as further moistening occurs. && .AVIATION... 051940Z...Coast...VFR conditions prevailing through 02Z, with OVC006- 010 tops 015 redeveloping after, spreading 10 mi inland affecting KSNA/KSAN/KCRQ. Areas VIS 3-5 SM 06/10-16Z, mainly affecting coastal mesas and higher coastal terrain. Slight chance of lightning after midnight. Low confidence. Valleys/Mountains/Deserts...FEW-SCT high clouds AOA 20,000 ft MSL and unrestricted VIS through Tuesday PM. Slight chance of lightning after midnight SD and southern Riverside Counties, then over the mountains Tuesday afternoon. Low confidence. && .MARINE... NW gusting to around 20 kt winds will occur near San Clemente Island each evening through Wednesday. Otherwise, no hazardous marine weather is expected through Friday. Slight chance of lightning near San Diego County coast tonight into Tuesday, but confidence is low. && .BEACHES... Slight chance of lightning tonight into Tuesday. Low confidence. && .SKYWARN... Skywarn activation is not requested. However weather spotters are encouraged to report significant weather conditions. && .SGX WATCHES/WARNINGS/ADVISORIES... CA...Heat Advisory until 8 PM PDT this evening for San Bernardino and Riverside County Valleys-The Inland Empire. Excessive Heat Warning until 8 PM PDT this evening for Apple and Lucerne Valleys-Coachella Valley-San Diego County Deserts- San Gorgonio Pass Near Banning. PZ...NONE. && $$ PUBLIC...Gregoria AVIATION/MARINE...Rodriguez