Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/27/18

remains on track and the previous forecast discussion and an
updated aviation discussion are below. STP
&& .SHORT TERM...valid for Fri and Sat... Scattered showers and thunderstorms are ongoing over southern MT and northern WY this afternoon. These showers and thunderstorms should move southeastward for the rest of this afternoon and evening thanks to strong northwesterly flow aloft. Over south central MT and north central WY, RAP guidance shows 0-6 km bulk shear values of 40 to 50 knots and NUCAPS soundings from earlier this afternoon showed a few pockets of appreciable instability under mostly sunny skies. These ingredients support a few strong to severe thunderstorms over those same areas through this evening. Upper-air disturbances will continue to move over the region tonight through Saturday, bringing additional periods of showers and thunderstorms. There is a low risk of a strong to severe thunderstorm Friday afternoon-evening over far southeastern Montana and Sheridan County...but cloud cover from morning convection could limit convective development in the afternoon. However, if skies can clear during the day Friday, sufficient shear would be in place to produce strong thunderstorms. High temperatures on Friday and Saturday will be below normal, generally in the middle 70s to near 80 degrees. RMS/borsum .LONG TERM...valid for Sun...Mon...Tue...Wed...Thu... Transition in the extended period as heights begin to build bringing a period of much warmer weather. Sunday through Wednesday a ridge of high pressure dominates bringing mainly dry weather and temperatures in the 90s. Normally this time of year humidity in the teens would be expected but with still green vegetation in many areas and a prevailing easterly surface flow this could keep humidities from falling below 20 percent. Ridge breaks down on Thursday but the time of this breakdown has been slipping consistently each run so the heat spell may last longer than currently depicted. The front breaking down the ridge could bring a round of thunderstorms Thursday. A consistent period of lower heights follows for Friday into Saturday as a weak wave moves through the area for of cooler temperatures and a chance for thunderstorms. borsum && .AVIATION... Isolated to scattered showers and thunderstorms will continue overnight into Friday across portions of the area. In general, VFR will prevail with MVFR possible under the heaviest shower/thunderstorm activity. Mountains may occasionally be obscured. STP && .PRELIMINARY POINT TEMP/POPS... Fri Sat Sun Mon Tue Wed Thu ----------------------------------------------------------- BIL 057/077 056/078 056/084 057/091 061/094 063/090 059/084 34/T 43/T 21/U 00/U 01/U 11/U 11/U LVM 050/078 048/077 047/080 048/088 053/089 054/085 051/080 33/T 43/T 21/U 00/U 11/U 11/U 10/U HDN 056/080 054/081 055/083 054/091 059/094 062/090 059/085 44/T 43/T 22/T 00/U 01/U 11/U 11/U MLS 057/078 054/080 056/081 056/088 060/093 064/090 060/083 34/T 42/T 22/T 00/U 00/U 01/B 11/U 4BQ 055/079 054/079 055/079 055/087 059/092 064/092 061/085 44/T 43/T 23/T 00/U 00/U 01/U 11/U BHK 053/075 051/076 052/079 054/086 057/090 061/088 057/081 13/T 32/T 22/T 01/U 00/U 01/B 11/B SHR 054/078 051/077 051/079 049/086 055/091 058/088 055/083 45/T 45/T 23/T 00/U 11/U 11/U 11/U && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$
Area Forecast Discussion
National Weather Service Cheyenne WY
420 PM MDT Thu Jul 26 2018 .SHORT TERM...(This evening through Friday) Issued at 300 PM MDT Thu Jul 26 2018 Severe weather ongoing across southeast Wyoming as we get an early start today. Forecast challenges deal with severe convection and possibility of heavy rain both today and Friday. Currently...Water vapor imagery showing an upper level shortwave tracking into the CWFA that has kicked off convection. SPC Mesoanalysis page showing an uncapped environment with surface based CAPE around 2000-2500J/KG already this afternoon at 2PM. Bulk shear around 40-45kts as well. Both CAPE and shear are expected to continue increasing through the rest of the afternoon. CAPE expected to peak out around 3000-3500 J/KG at 6PM and bulk shear increases to 50-55kts. Large hail, damaging winds and a few tornadoes can not be ruled out. PWATs in excess of 1 inch continue across our eastern counties through the afternoon, so existing Flash Flood Watch will remain in effect. HRRR continues to show pretty strong cells across the area through roughly 03Z before beginning to ease. Forecast still on track for severe weather Friday as another shortwave tracks into the Nebraska Panhandle. ECMWF continues to show the best area for severe storms Friday to be over the Panhandle where SPC has an Enhanced Risk for severe storms. Heavy rainfall expected out there Friday, so later shifts will need to consider another Flash Flood Watch once again. .LONG TERM...(Friday night through Thursday) Issued at 307 AM MDT Thu Jul 26 2018 The wet and unsettled conditions will remain over the area Saturday through Sunday with a pretty good push of cool air for late July arriving Sunday. Scattered to numerous showers and storms will continue both days. Drying should then ensue late Sunday in the wake of a stronger shortwave that will move south from the northern plains and cut off the monsoonal moisture for a time. Monday through Weds should see warming temperatures back to near seasonal averages along with mainly dry conditions under a persistent northwesterly flow aloft. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 417 PM MDT Thu Jul 26 2018 Round #2 of thunderstorms beginning to develop along the Laramie Range late this afternoon. Using latest HRRR guidance shows the storms impacting KCYS and Nebraska Panhandle airports through the 03-04Z timeframe. Could see stratus redevelop tonight for those airfields that receive heavy rainfall this evening. More widespread showers and thunderstorms expected for the Panhandle airports Friday afternoon. && .FIRE WEATHER... Issued at 300 PM MDT Thu Jul 26 2018 Minimal fire weather concerns over the next few days as monsoon moisture remains in place. Widespread wetting rains expected with well above critical humidity in the afternoon. Expect showers and thunderstorms to continue through Sunday, before drying commences next week. Until then, fire weather threats will remain low. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Flash Flood Watch until 10 PM MDT this evening for WYZ108-118- 119. NE...Flash Flood Watch until 10 PM MDT this evening for NEZ003- 019>021-054-055-096. && $$ SHORT TERM...GCC LONG TERM...RE AVIATION...GCC FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service El Paso Tx/Santa Teresa NM
304 PM MDT Thu Jul 26 2018 .SYNOPSIS... A weak backdoor cold front located just west of the Rio Grande will help increase moisture over the area, leading to scattered thunderstorms this evening over much of the desert lowlands, especially east of El Paso. Another preferred area for thunderstorms this evening will be in southern Grant, Luna, and western Dona Ana Counties. A few showers and thunderstorms will linger after midnight across the region. Thunderstorm chances will begin to wane again Friday and Saturday, with the focus shifting to the Gila Region and the lowlands closer to the Arizona border. Another backdoor front will enhance precipitation chances Monday afternoon and through at least the middle of the week. && .DISCUSSION... Backdoor cold front, or at least the wind shift preceding it, has pushed just west of the Rio Grande (roughly). RAP analysis shows CAPE values of 2000-3000 J/Kg behind the front, though this is likely overdone, with weakening CIN. Modifying the 12Z RAOB for current surface conditions yields SBCAPE of 1035 J/Kg, with a capping inversion around 600 mb (CIN of just -2), assuming no mid-level warming or cooling since 12Z. Cu is still mostly flat in the lowlands, though it is expanding in coverage east of the Franklins. Will keep the afternoon/evening PoPs unchanged, and suspect storms will fire in Eastern EP County as outflow from Hudspeth County moves west. Some isolated stronger storms have produced impressive rain rates in parts of the Gila, with a recent spotter call from Pinos Altos reporting 0.40" of rain in ten minutes, mixed with pea-sized hail. These storms have been on a weakening trend, but additional storms will likely pulse up-and-down through the remainder of the afternoon. Instability is much weaker in SW New Mexico, with CAPEs generally around 400-600 J/Kg per the RAP, and a little higher over the Bootheel. Conditions should modify some as the front tries to push west towards the divide this afternoon/evening, and we`ll have to watch for outflow interactions this evening in the southern Grant/Luna/Western Dona Ana County area. By early evening, I expect the backdoor front will be pretty well ill- defined with not enough convergence itself to initiate convection unless or until it is enhanced by outflow coming in from the east. Locally heavy rainfall will continue to be the main concern with these storms, with a secondary risk of strong wind gusts (50-60 mph) in a few storms as they develop or move into the lowland deserts. Expect at least isolated showers/thunderstorms lingering after midnight given the northerly flow continuing like the past few nights, and weak upstream disturbances dropping in. For tomorrow, some low-level drier air tries to work in from the SE (an unusual direction for drying). This, coupled with warming aloft will limit instability east of the Rio Grande. The best chance for thunderstorms will be in the Gila Region in the afternoon, dropping south to southwest towards the Bootheel in the evening. Scattered thunderstorms also are a good bet in the Sacramento Mountains, but they will struggle to work into the lowland deserts. Saturday looks much like Sunday, except with the stable air continuing to work westward, and slight veering in the steering winds shifting the risk of lowland storms in SW New Mexico a little closer to the Arizona line. Coverage over the Sacramentos looks to become limited as well. For the longer range, GFS, its ensembles, and the ECMWF are in good agreement on the overall pattern, keeping the subtropical ridge stuck over the Lower Colorado basin with continued troughing over the Mississippi Valley. New Mexico and Far West Texas will stay in a northerly flow aloft. This will invite another backdoor front to push into the area Monday afternoon or evening, increasing precip chances through at least the first half of next week. && .AVIATION... Valid 27/00Z-28/00Z... Scattered to numerous 1-3SM TSRA BKN030-050 expected across the area to start the period under prevailing SCT-BKN080-100 BKN120-150. Activity should generally move south of border by 06Z with just some light rain showers and isolated thunder possible through overnight. After 12Z expect SCT080-100 SCT-BKN200-250 for remainder of period with scattered 3-5SM -TSRA BKN040-060 mountains and isolated over the lowlands. Winds mainly E to SE AOB 12KTS except near thunderstorms where gusts to 40KTS possible. && .FIRE WEATHER... This afternoon and evening looks to be the most active one until at least Monday. Plenty of moisture has moved into the area and a weak frontal boundary is moving westward across the Borderland this afternoon/evening. Greatest activity will occur over area mountains with locally heavy rain and flooding possible. Drier more stable air will be entering in for Friday into the weekend with any activity mainly confined to area mountains and locations near the Arizona border. Moisture surge comes back Monday with more widespread thunderstorm activity expected through midweek. Temperatures will remain near to slightly above average with winds light except near thunderstorms. && .PRELIMINARY POINT TEMPS/POPS... El Paso 74 95 73 97 / 20 0 10 0 Sierra Blanca 68 92 69 94 / 20 0 0 0 Las Cruces 71 93 68 95 / 50 10 10 0 Alamogordo 69 91 70 94 / 30 20 20 0 Cloudcroft 53 70 54 73 / 30 60 30 20 Truth or Consequences 70 89 69 94 / 60 10 30 10 Silver City 65 85 63 87 / 50 50 50 40 Deming 70 92 68 95 / 60 20 30 10 Lordsburg 71 92 69 94 / 50 20 50 20 West El Paso Metro 73 93 73 96 / 30 0 10 0 Dell City 70 96 70 97 / 20 0 0 0 Fort Hancock 71 96 72 98 / 20 0 0 0 Loma Linda 68 91 68 93 / 20 0 10 0 Fabens 70 95 71 97 / 20 0 10 0 Santa Teresa 71 94 71 95 / 30 0 10 0 White Sands HQ 71 92 70 95 / 30 0 10 0 Jornada Range 69 92 68 95 / 40 10 20 0 Hatch 70 93 69 96 / 60 10 20 0 Columbus 73 94 71 96 / 60 10 20 10 Orogrande 71 93 71 95 / 30 0 10 0 Mayhill 57 78 58 82 / 30 50 20 20 Mescalero 58 78 58 82 / 30 60 40 20 Timberon 58 78 58 81 / 30 30 10 10 Winston 60 83 59 87 / 60 40 60 30 Hillsboro 66 89 65 91 / 60 30 30 20 Spaceport 68 91 68 94 / 40 10 20 0 Lake Roberts 58 83 57 86 / 50 60 50 50 Hurley 65 86 64 88 / 50 40 40 30 Cliff 63 90 63 92 / 40 60 50 30 Mule Creek 65 91 64 90 / 30 50 60 40 Faywood 67 88 65 89 / 60 20 30 20 Animas 71 93 69 94 / 50 20 50 20 Hachita 70 93 68 94 / 60 20 30 20 Antelope Wells 69 92 68 92 / 40 30 50 30 Cloverdale 66 89 65 88 / 40 30 60 30 && .EPZ WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$ 25-Hardiman / 26-Grzywacz
Area Forecast Discussion
National Weather Service Goodland KS
528 PM MDT Thu Jul 26 2018 .SHORT TERM...(This evening through Friday) Issued at 234 PM MDT Thu Jul 26 2018 Northwest flow continues over the High Plains over a broad, but weak, southeasterly low level flow. The directional shear is resulting in rather large deep layer shear values of 50kts this afternoon, which combined with weak to moderate instability has resulted in an environment favorable for rotating updrafts. Moisture is also plentiful, with precipitable water values of 1-1.5 inches and surface dew points in the 60s. Perhaps the one lacking ingredient for more widespread convection is lift, with only the hint of shortwave trough embedded in the northwest flow. There is the tail end of an old front/outflow boundary located north to south in northwest Colorado which may be a focus for convection. Expect storms to continue to increase in coverage this afternoon and evening as the upper shortwave moves across. HRRR continues to suggest an MCS/thunderstorm cluster moving south out of Nebraska and along the Colorado/Kansas border area late tonight and during the overnight, possible posing a damaging wind gust threat in those areas. Storm motions are rather fast at around 15kt and any right movers at 20-30kts, so despite the high moisture not anticipating a flash flood threat tonight. As has been the case the last few mornings, patchy dense fog will develop overnight and persist into early Friday morning before dissipating. Not much changes for the general set up on Friday afternoon. Another weak shortwave trough comes through in the northwest flow, with impressive deep layer shear and even more instability than today. Scattered afternoon storms will develop, some severe, with large hail and damaging winds the main threats. Better chances will occur Friday evening with SPC upgrading to an enhanced risk (see Long Term section). High temperatures on Friday will be in the lower 80s. .LONG TERM...(Friday night through Thursday) Issued at 151 PM MDT Thu Jul 26 2018 At the start of the long term, an upper high continues over the desert southwest with troughing and an upper low pressure system extending from southeastern Canada into the eastern CONUS. Between these two features, fast northwest flow aloft is expected over the tri-state region. Friday evening and overnight appears to be an interesting period. A weak shortwave passing through the northwest flow and a surface boundary coming down from Nebraska will aid in the development of thunderstorms. With near 2500 J/kg of CAPE, ample shear of 50 knots or greater, steep lapse rates and good moisture in place, severe thunderstorms are expected. Exact locations are still in question. However, it appears that storms should fire over higher terrain west- northwest of the CWA during the afternoon hours, with shear supporting supercell development. Heading into the evening and overnight, storms should congeal into a line, traveling southeastward across the region. The main threats will be damaging winds and large hail. Guidance including PWATS of 1 to 2 inches suggest that heavy rainfall will be a concern as well. A similar pattern remains in place through the weekend and unsettled weather is anticipated to continue. Additional disturbances will pass through the northwest flow (including a strong shortwave late Sunday), generating storm chances through Monday morning. Severe storms cannot be ruled out on Saturday and Sunday depending on how well the lower levels recover from the previous day`s convection. Will continue to monitor in the coming days. Drier air and surface high pressure move into the area on Monday, resulting in a dry forecast through Thursday. High temperatures decrease from the 80s on Saturday to the mid 70s to low 80s on Sunday and Monday. Temperatures increase thereafter, reaching the low 90s on Thursday. Low temperatures range from the mid 50s to mid 60s. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 519 PM MDT Thu Jul 26 2018 Thunderstorm complexes will be affecting both Kgld and Kmck in the first few hours of the period. Mvfr conditions with occasional ifr conditions can be expected with variable wind gusts to around 45 knots. After that both sites will have vcts to account for continued thunderstorm activity. Kmck should see activity through the evening. However, thunderstorms could be near Kgld until 11z. Outside of thunderstorms, the winds will be variable in direction from the south to southeast at 5 to 15 mph. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...024 LONG TERM...JBH AVIATION...BULLER
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
430 PM PDT Thu Jul 26 2018 .UPDATE...Updated air quality issues section. && .SYNOPSIS... A ridge of high pressure will persist for the next several days. Excessive heat continues through the end of the week. A bit cooler starting this weekend but temperatures remaining above normal. && .DISCUSSION... Thunderstorms formed earlier today over the high sierra. Storms activity more widespread due to an increase in mid to upper level moisture coming off pacific on a SSW flow. Thus far smoke from the Ferguson fire remains limited towards the Mariposa area. Smoke starting to move northward this afternoon. HRRR model progs smoke coming down the foothills and east side of the valley tonight as the night time inversion sets up. Little change in the short term with a ridge centered over the Colorado river persisting and keeping excessive heat across the central CA interior into the weekend. The ridge shifts a bit inland Saturday so not as hot on Saturday with temperatures bit cooler in the San Joaquin Valley. However guidance shows excessive heat conditions continuing across the Mojave desert area into the weekend. Hence the heat warming for E Kern County has been extended through Saturday. The ridge of high pressure has been keeping us several degrees above average for weeks now, and it look like it will remain anchored over the area and not let up very much any time soon. Some moisture from Mexico will move around the south and west side of the ridge early next week and bring a threat of convective storms mainly over sierra mountains. && .AVIATION... Areas of MVFR visibility in smoke will continue in the vicinity of the Ferguson Fire in Mariposa County for at least the next 24 hours. Isolated thunderstorms will be possible near the southern Sierra crest through 04Z Fri. Otherwise, VFR conditions will prevail over the central CA interior during the next 24 hours. && .AIR QUALITY ISSUES... SFOAQAHNX for an Air Quality Alerts && .CERTAINTY... The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is medium. Certainty levels include low...medium...and high. Please visit for additional information an/or to provide feedback. && .HNX Watches/Warnings/Advisories... Heat Advisory until 9 PM PDT Friday CAZ089>095. Excessive Heat Warning until 8 PM PDT Saturday CAZ098-099. && $$ public...MV avn/fw...JEB synopsis...MV
Area Forecast Discussion
National Weather Service Northern Indiana
812 PM EDT Thu Jul 26 2018 .SYNOPSIS... Issued at 649 PM EDT Thu Jul 26 2018 Cooler and less humid air will spread across the region tonight and last into the weekend. A few clouds will form along and south of Lake Michigan during the day Friday, however no precipiation is expected. Lows tonight will drop into the upper 50s to around 60. Cooler and less humid conditions can be expected for Friday with highs only reaching into the mid 70s. && .SHORT TERM...(This Evening through Friday) Issued at 341 PM EDT Thu Jul 26 2018 The next upstream short wave across the western Great Lakes continues to impinge on the frontal zone across northern Indiana/northwest Ohio this afternoon. Approach of this wave and favorable upper jet dynamics have been enough to initiate storms this afternoon. Shear profiles are robust with mid/upper level jet streak impinging on the area, and 35-45 knots of effective shear. Earlier mid level cloud deck has dissipated across the area allowing sfc temperatures to recover into the lower 80s. Narrow frontal/pre- frontal instability axis noted per RAP analyses with axis of 1500-2000 MLCAPES from MZZ to DFI, and DCAPES on the order of 1000 J/kg. Sharp mid level theta-e minimum, steep low level lapse rates, and precip loading still argue for isolated damaging wind gusts as the primary severe threat generally along/east of I-69 and south of US Route 30. However, cannot completely rule out isolated large hail given relatively low wet bulbs and periodic better mid level rotation with a few of the cores promoting hail growth. Lack of strong frontal low level convergence fields and modest instability should keep threat more isolated in nature at best however. Still expecting isolated severe threat to exit far southeast portions of the area by the 23Z timeframe. Otherwise, mainly quiet conditions for the remainder of the night as cool/dry advection occurs allowing mins to bottom out around 60 or the upper 50s. Friday will feature much below normal temperatures in the 70s with partly sunny skies. Large negative height anomaly across the Upper MS Valley this afternoon will settle across the Great Lakes region on Friday with a very low probability of diurnally driven isolated showers. Moisture looks to be quite limited and will not include any mentionable PoPs at this time for Friday, although may need to eventually add an isolated mention. && .LONG TERM...(Friday Night through Thursday) Issued at 341 PM EDT Thu Jul 26 2018 Upper low level will lift across eastern Ontario/western Quebec early Saturday as next upper level trough begins to dig across southern Alberta/Montana. Local area should be situated in break between better precip chances for Saturday. By Sunday-Monday, southward digging upstream wave across the Rockies should begin to induce a broad downstream isentropic lift/fgen response across southern Great Lakes/Ohio Valley for additional shower/storm chances. This wave will be slow to dampen as it eventually gets absorbed by the northern stream late work week. Slow progression of this pattern will result in several periods of rain chances for next week with continued below normal temperatures. && .AVIATION...(For the 00Z TAFS through 00Z Friday Evening) Issued at 649 PM EDT Thu Jul 26 2018 NW flow has spread over the forecast area. VFR conditions to prevail through 15Z. Cu and strato-cu formation lee of Lake Michigan will be thickest near KSBN with isold MVFR CIGS - significantly less coverage toward KFWA. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...Beach Hazards Statement until 7 PM EDT this evening for MIZ077. OH...NONE. LM...NONE. && $$ SYNOPSIS...Lewis SHORT TERM...Marsili LONG TERM...Marsili AVIATION...Lewis Visit us at Follow us on Facebook...Twitter...and YouTube at:
Area Forecast Discussion
National Weather Service Jacksonville FL
839 PM EDT Thu Jul 26 2018 .UPDATE... Remaining convection over southeast Georgia should diminish before midnight. HRRR is trying to bring some convection over metro Jacksonville overnight but not seeing any indications that the model is onto something here so will not bite on it. Overall might see some light ground fog in inland locations toward sunrise. && .AVIATION...Only issue at the fields tonight might be some light ground fog/mist at Cecil Airport/VQQ and Gainesville Regional/GNV. Otherwise VFR conditions expected overnight. && .MARINE...Surface ridge will build south of the waters the next couple of days then build over the waters over the weekend. Winds generally south southwest 10 to 15 knots except southeast near the coast in the afternoon. Seas 2 to 4 feet. Scattered mainly afternoon and evening showers and thunderstorms. Rip Currents: Moderate risk of rip currents for Georgia and a high risk for Florida on Friday. The rip current risk will remain elevated over the weekend due to a long fetch of SSE winds and persistent long period swell. && .PRELIMINARY POINT TEMPS/POPS... AMG 74 92 73 91 / 30 40 30 40 SSI 78 90 76 89 / 20 30 40 40 JAX 74 93 74 92 / 20 30 20 40 SGJ 76 91 74 89 / 20 40 20 40 GNV 73 92 73 91 / 20 30 10 40 OCF 73 92 73 91 / 20 30 10 50 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && $$ Sandrik/Nelson/McGinnis
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
959 PM EDT Thu Jul 26 2018 .SYNOPSIS... A stationary boundary will linger over the middle of the state into this weekend, lifting to the north early next week. Bermuda high pressure will remain anchored over the SW Atlantic into next week while a broad trough of low pressure sits over the lower MS River Valley. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 955 PM Thursday...For the first time in awhile, we have a quiet radar across eastern NC at late evening as earlier isolated convection has dissipate with loss of daytime heating. High-resolution models such as the HRRR and 3km NAM continue to indicate showers/storms will develop after 2 or 3 AM and skirt the coastal counties. Will continue previous forecast of a slight chance PoP in these areas. Seasonal lows mainly in the lower to mid 70s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/... As of 320 pm Thu...Offshore showers/storms early will migrate inland through the day, first along the coast in the morning then transitioning to afternoon convection for interior zones in the afternoon. Activity should be scattered in nature so no higher than 30% PoPs at this time. Highs more typical for the peak of the summer in the upper 80s interior to mid 80s coast. && .LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/... As of 345 AM Thu...Models remain in good agreement with the typical summertime pattern with scattered shower and storm chances each day as fairly active regime sets in again across Eastern NC. Friday night through Monday...26/00Z med range model suite in fairly good agreement with synoptic regime this time period. Broad upr trough will amplify across the Great Lakes region and dig into the lower MS River Valley this weekend, with sfc front sagging south into the Mid Atlantic to Southeast states. It appears front will remain north and west of E NC which is typical for the peak of the summer, though hts fall enough to warrant somewhat better chances of showers/storms for the weekend into early next week as convective coverage will be a bit more widespread than typical, esp for interior zones. Relatively deep moisture in the column will be present and mean that precip will be a threat even during the evening and overnight as low lvl flow is off the Atlantic and GOM. Afternoon highs near avg in the mid/upr 80s. Overnight lows also seasonably warm in the 70s. Tuesday through Wednesday...The mid week period may finally return to a drier than avg regime as strong subtropical ridge builds westward towards the eastern seaboard and forces stagnant upper trough to the west to retreat. More typical afternoon/early evening iso to sct convection with best chances along inland moving sea breeze each afternoon. Temps remain near seasonable vals in the upper 80s inland to mid 80s coast and lows in the 70s. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Short Term /through Fri/ As of 620 pm Thu...VFR should continue through midnight with dry conditions forecast overnight. Some IFR/MVFR ceilings could be possible early tomorrow morning with low level stratus or isolated fog. VFR should continue Fri with brief Sub-VFR in scattered convection possible at any of the 4 terminals during the afternoon. Light SSW surface winds around 5 knots through the short term. Long Term /Fri through Monday/... As of 345 AM Thu...A return to mainly VFR Friday as typical summertime pattern returns with just scattered to isolated showers/storms in the afternoon. Perhaps better chance of lowered vsbys/cigs this weekend into early next week as better chances for showers/storms moves in. && .MARINE... Short Term /through Fri/ As of 10 PM Thursday...Only minor changes needed to the current marine forecast. Winds are S/SW 5-15 knots with seas 3-4 feet with a few 5-footers over the outer waters. These conditions should linger overnight and on Friday. Long Term /Fri through Monday/... As of 345 AM Thu...Winds and seas typical of mid-summer Bermuda high pattern with SW winds 5-15 kt through the period, highest outer waters. Seas will generally be 3-5 ft through Sat central and southern waters, with 2-4 ft north of Oregon Inlet, then 2-4 ft all waters by Sunday and into Monday. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...Beach Hazards Statement through Friday evening for NCZ095-098- 103-104. MARINE...None. && $$ SYNOPSIS...HSA NEAR TERM...CTC/BAB SHORT TERM...HSA LONG TERM...TL AVIATION...CTC/HSA/TL/BAB MARINE...CTC/HSA/TL/BAB
Area Forecast Discussion
National Weather Service Phoenix AZ
858 PM MST Thu Jul 26 2018 .SYNOPSIS... Excessively hot weather will continue across southeast California through Friday and across portions of southwest Arizona through this evening. Moisture will slowly move back into the region over the next few days allowing temperatures to eventually retreat back to near normal levels by the weekend. In addition, more expansive thunderstorms will begin over higher terrain areas of Arizona, then gradually spread towards lower elevation communities during the weekend and early next week. && .DISCUSSION... Thunderstorm activity has largely been confined to the fringes of the lower deserts, especially to the north of the Phoenix area. Isolated thunderstorm development continues to occur south of Florence this evening, but the primary effect across the lower deserts remains a multitude of outflow boundaries. The 00Z and 03Z soundings from Phoenix continue to show steep mid-level lapse rates in place. However, two capping inversions are notable, one near 3 km AGL and another above 6 km AGL, that are likely inhibiting convective development across the lower deserts. Thus, potential for thunderstorms will remain quite low. Various versions of the HRRR do try to paint some potential for isolated shower/thunderstorm development overnight into southwest Arizona, but with poor run-to-run consistency and lack of any coherent signal, confidence remains quite low in this scenario. && .PREVIOUS DISCUSSION... Model guidance shows some cooling into Friday, but not enough across southeast California, so we have extended the warning another day for that area. Eventually moisture will overspread the entire region starting this weekend and the high pressure ridge weakens further allowing highs to fall back within a few degrees of normals. Moisture levels are expected to begin to gradually increase on Friday. This moisture increase, along with steep mid level lapse rates and the very hot conditions will likely lead at least slight chances for showers and thunderstorms over the lower deserts of south-central AZ, with better chances over the higher terrain north and east of Phoenix. The main threat from these storms will be strong outflow winds and brief heavy rains. As the upper level high center shifts a bit northward into northern Arizona this weekend, deeper easterly flow will advect in more substantial moisture. This should bring widespread 1000-700mb mixing ratios of 10-13 g/kg by Saturday afternoon which will boost CAPES to above 1000 J/kg. There are no large inverted troughs seen in the models, but the GFS does bring a minor IT into southern Arizona on Saturday while the European keeps it mostly over Sonora Mexico. Storm chances improve greatly starting Saturday with the higher moisture levels and instability, but steering flow will continue to be very weak. The main threats from thunderstorms this weekend will be strong wind gusts, blowing dust and localized flooding. Little change is seen going into next week with moisture levels remaining modestly high and the upper high center situated just to our north. The flow around the high should continue to bring moisture out of the east/northeast and the occasional inverted trough while providing day to day storm chances over much of the region. && .AVIATION... South-Central Arizona including KPHX, KIWA, and KSDL: South-Central Arizona including KPHX, KIWA, and KSDL... Primary concern will surround the uncertainty of outflow boundary motions and maintenance across the Phoenix metro area this evening. A strong outflow boundary moved southward earlier from northern Maricopa County, while additional weaker boundaries have since been detected. The potential for an earlier switch out of the east remains in association with these boundaries, but confidence in wind direction will remain low through around 10Z. Otherwise, a more predominant easterly wind should take hold with typical diurnal wind shifts occurring. The potential for any thunderstorms across the Phoenix area will remain low overnight. Southeast California/Southwest Arizona including KIPL and KBLH: Terminals will remain dry for the next 24 hours as there is little to no chance of thunderstorms over the area. Only FEW to BKN high clouds are expected as surface winds follow typical diurnal patterns. Aviation Discussion not updated for amended TAFs. && FIRE WEATHER... Sunday through Thursday: Isolated to scattered showers and thunderstorms are expected to develop on Sunday afternoon and evening over the higher terrain north and east of Phoenix before pushing into the lower deserts. Although rain chances will decrease slightly for Monday into the middle of next week, moisture levels should easily support at least isolated convective activity over the higher terrain which may push into the lower deserts. Minimum relative humidity values will remain above 20 percent overnight with winds generally remaining below 15 mph aside from thunderstorm outflows and westerly 20-25 mph wind gusts. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Excessive Heat Warning until 8 PM MST Friday for AZZ530. CA...Excessive Heat Warning until 8 PM PDT Friday for CAZ560>563- 566>570. && $$ DISCUSSION...Rogers PREVIOUS DISCUSSION...Kuhlman AVIATION...Rogers/Wilson FIRE WEATHER...Percha/Hopper
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
807 PM EDT Thu Jul 26 2018 .UPDATE... A weak boundary is draped across central Florida and into the eastern Gulf, with deep moisture and favorable dynamics allowing for scattered to numerous showers and thunderstorms to develop from around Interstate 4 north this afternoon. South of Interstate 4, broad subsidence kept conditions mostly dry throughout the afternoon. Thunderstorms have largely dissipated across the area, except for a few isolated showers off the southwest Florida coast. HRRR and other high resolution short range models are showing thunderstorms developing pre-sunrise over the eastern Gulf along the weak boundary and moving into the Tampa Bay area. Rain chances during the early morning hours were bumped up slightly to account for these showers. The only other significant forecast change was to increase rain chances slightly Friday afternoon. No other changes are planned for the evening update. && .AVIATION... VFR conditions are expected to continue to hold through much of the evening hours. Showers and storms are expected to develop over the Gulf and move into the Tampa Bay area after around 08z, potentially impacting KPIE, KTPA, and KSRQ. Other terminals could see showers or storms moving inland after sunrise. Thunderstorms will also develop over the land during the late morning and afternoon, largely clearing out and moving inland by the late afternoon. && .MARINE... Light westerly winds will continue through Friday, with early morning showers and thunderstorms expected to develop over the easterly Gulf and move inland through the early afternoon. The Atlantic ridge of high pressure will build into the eastern Gulf this weekend, setting up a more southerly flow pattern through early next week, with winds turning onshore with the afternoon sea breeze. Wind and seas will generally remain less than headline criteria, outside of daily thunderstorms which will create locally hazardous boating conditions. && .Preliminary Point Temps/PoPs... TPA 78 90 78 90 / 30 20 10 60 FMY 77 92 77 91 / 10 40 40 70 GIF 76 93 76 91 / 10 40 40 70 SRQ 78 91 79 89 / 20 20 10 50 BKV 74 91 74 90 / 20 30 10 50 SPG 79 90 79 90 / 30 30 10 50 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...Beach Hazards Statement through Monday evening for Coastal Charlotte-Coastal Lee-Coastal Sarasota. Gulf waters...None. && $$ UPDATE/AVIATION/MARINE...18/Fleming UPPER AIR...27/Shiveley DECISION SUPPORT...13/Oglesby