• UTC: 2017-06-23 22:12

  • SPC Jun 23, 2017 1730 UTC Day 2 Convective Outlook
    on June 23, 2017 at 5:24 pm

    SPC 1730Z Day 2 Outlook Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1221 PM CDT Fri Jun 23 2017 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHEAST... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER NEW MEXICO... ...SUMMARY... Isolated strong storms with gusty winds are possible over portions of the Southeast on Saturday, with isolated hail or wind over parts of New Mexico. ...Southeast... Remnants of Cindy are expected to translate off the Middle Atlantic Coast early in the day2 period and upper ridging will be suppressed across the Southeast as a broader trough begins to establish itself over the eastern US. As this occurs, pre-frontal trough will ease into the Carolinas/GA which should provide the focus for convection Saturday. While mid-level lapse rates will remain poor, roughly moist-adiabatic, some boundary-layer heating is expected from southern GA into coastal Carolina such that modest buoyancy should develop by mid-day ahead of the aforementioned zone of low-level confluence. Convection that evolves across the Southeast will do so within a zone of modest deep-layer shear that could support gusty winds with the strongest storms. ....New Mexico... Deep northwesterly flow across the northern/central Plains will be conducive for surface ridge to build south into the high Plains of TX/NM. Upslope flow will develop early in the period across this region forcing moisture deep into the southern Rockies. As the surface ridge strengthens over the southern Plains, strong heating along the western edge of this moisture field should contribute to significant buoyancy and strong thunderstorms will likely develop over portions of NM. Forecast soundings favor rotating updrafts and a few supercells may ultimately evolve which would propagate south along an instability axis toward northern Mexico during the late evening/overnight hours. Hail/wind can be expected with the most robust convection across this region given the steep lapse rates expected. ..Darrow.. 06/23/2017 Read mor […]

  • SPC MD 1132
    on June 23, 2017 at 5:23 pm

    MD 1132 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF FAR SOUTHERN MO...EASTERN OK...AND AR Mesoscale Discussion 1132 NWS Storm Prediction Center Norman OK 1222 PM CDT Fri Jun 23 2017 Areas affected...Portions of far southern MO...eastern OK...and AR Concerning...Severe potential...Watch possible Valid 231722Z - 231945Z Probability of Watch Issuance...40 percent SUMMARY...Convection across southeastern MO may gradually organize into a line of storms across northern AR/eastern OK over the next several hours. Strong to locally damaging winds should be the main threat with this activity, and watch issuance is possible this afternoon. DISCUSSION...A cluster of thunderstorms is occurring along a cold front across southwestern MO as of 17Z. In addition to the low-level forcing of the front, at least the glancing influence of large-scale ascent associated with a shortwave trough over western/central KS will likely aid sustained convection across this region through the afternoon and early evening. A very moist low-level airmass is present across AR and far eastern MO based on the 12Z sounding from LZK and latest surface observations indicating dewpoints remain in the low to mid 70s. Surface temperatures have already warmed into the 80s downstream of ongoing convection. Additional diurnal heating and modestly steepened mid-level lapse rates (generally 6.5-7.5 C/km in the 700-500 mb layer) overspreading eastern OK into AR should further increase instability early this afternoon, with MLCAPE values of 2000-3000 J/kg becoming common through peak heating. Mid-level winds will likely remain somewhat modest, as stronger flow aloft remains displaced to the north. But, around 25-30 kt of northwesterly flow around 500 mb should support at least a semi-organized line of thunderstorms moving southeastward across eastern OK into AR this afternoon and early evening. Additional storms may form along the cold front in eastern OK. Given the linear mode expected, strong to damaging winds would likely be the main threat, although marginally severe hail could also occur with the strongest cores embedded within the line. The lack of even stronger mid-level winds and related shear may temper the overall severe threat somewhat, but recent convection-allowing model guidance is generally consistent with the scenario described above. Watch issuance will be possible this afternoon based on short-term observational and radar trends. ..Gleason/Guyer.. 06/23/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...SGF...SHV...TSA...OUN... LAT...LON 33789405 33949501 34129578 35279605 36039582 36629468 36869399 36939295 36769218 36359158 35829137 34139140 33769223 33689298 33789405 Read mor […]

  • SPC MD 1131
    on June 23, 2017 at 5:16 pm

    MD 1131 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR NORTHERN KY...SOUTHERN/EASTERN OH...WESTERN WV...WESTERN PA Mesoscale Discussion 1131 NWS Storm Prediction Center Norman OK 1215 PM CDT Fri Jun 23 2017 Areas affected...Northern KY...Southern/eastern OH...Western WV...Western PA Concerning...Severe potential...Watch possible Valid 231715Z - 231915Z Probability of Watch Issuance...40 percent SUMMARY...A gradual increase in the threat for damaging wind gusts and perhaps a tornado or two is expected this afternoon. Watch issuance is possible. DISCUSSION...A gradual increase in the intensity and coverage of convection has been noted across portions of southern OH, in advance of a large precipitation shield (with embedded convection) further to the northwest. While midlevel lapse rates are poor, given the influence of the decaying tropical system to the southwest, modest heating within a very moist environment has resulted in moderate destabilization, with SBCAPE rising into the 1000-1500 J/kg range where temperatures have warmed into the low 80s F. Further intensification is possible, both with the more discrete activity across southern OH and northern KY, and within the larger convective plume across central/northern OH as that moves eastward. With strong deep-layer southwesterly flow over the region, effective shear has increased into the 40-50 kt range, which is more than sufficient for some organized storm structures. With unidirectional wind profiles in place, damaging wind gusts are expected to the primary threat, though low-level shear is sufficient for a tornado or two with any semi-discrete supercells that can evolve. Watch issuance is possible later this afternoon to cover this threat. ..Dean/Guyer.. 06/23/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PBZ...RLX...CLE...ILN... LAT...LON 38828510 39318455 39858324 40268227 40668151 41028071 41138003 40567974 40037995 39388077 38778161 38428240 38558365 38728470 38798507 38828510 Read mor […]

  • SPC Tornado Watch 365 Status Reports
    on June 23, 2017 at 5:15 pm

    WW 0365 Status Updates STATUS FOR WATCH 0365 HAS NOT BEEN ISSUED YET Read mor […]

  • SPC Tornado Watch 365
    on June 23, 2017 at 5:15 pm

    WW 365 TORNADO AL GA MS TN 231715Z - 240100Z URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 365 NWS Storm Prediction Center Norman OK 1215 PM CDT Fri Jun 23 2017 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Western and Northern Alabama Northwest Georgia Eastern Mississippi Middle and Eastern Tennessee * Effective this Friday afternoon and evening from 1215 PM until 800 PM CDT. * Primary threats include... A few tornadoes possible Isolated damaging wind gusts to 70 mph possible SUMMARY...Preceding the east/northeastward-moving remnants of Cindy, a very air mass and strong low/mid-level winds will support both organized bowing structures and some line-preceding or embedded supercells capable of a few tornadoes and locally damaging winds this afternoon into early evening. The tornado watch area is approximately along and 80 statute miles east and west of a line from 45 miles north northeast of Crossville TN to 20 miles south southwest of Tuscaloosa AL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24040. ...Guyer Read mor […]

  • SPC Day 2 Fire Weather Outlook
    on June 23, 2017 at 4:51 pm

    SPC Day 2 Fire Weather Outlook Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Fri Jun 23 2017 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... A few sporadic lightning strikes accompanied by minimal precipitation cannot be entirely ruled out over coastal CA as a plume of midlevel moisture elongates northward -- a regime continuation from the Day-1/Friday period. The overall dearth of larger-scale ascent interacting with the moisture plume is presently expected to limit dry-thunderstorm coverage. As such, dry-thunderstorm highlights have not been included. Otherwise, no changes have been made to the ongoing forecast. ..Cohen.. 06/23/2017 .PREV DISCUSSION... /ISSUED 0150 AM CDT Fri Jun 23 2017/ ...Synopsis... Upper troughing expected to cover much of the central and eastern CONUS at the beginning of the period will gradually shift eastward throughout the day as upper ridging expands west of the Rockies. At the surface, high pressure will spread southeastward across the Plains and mid/lower MS valley. Slight westward shift of the upper ridging across the western CONUS will allow more mid-level moisture into NM with scattered thunderstorms anticipated during the late afternoon across much of the state. Precipitable water over an inch and slow storm motions suggest mostly wetting rains. Hybrid storms are possible farther west over southeast AZ but low dry thunderstorm coverage precludes the need to delineate a dry thunderstorm area. Otherwise, no fire weather conditions are expected across the CONUS. ...Please see www.spc.noaa.gov/fire for graphic product... Read mor […]

  • SPC Day 1 Fire Weather Outlook
    on June 23, 2017 at 4:50 pm

    SPC Day 1 Fire Weather Outlook Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Fri Jun 23 2017 Valid 231700Z - 241200Z A plume of midlevel tropical moisture, and associated elevated buoyancy, will elongate northward near the Pacific Coast -- along the western flank of a building ridge. Any impulses embedded within the nebulously defined moisture stream should remain offshore, where a few lightning strikes could occur. Also, a few sporadic lightning strikes, accompanied by minimal precipitation, cannot be ruled out onshore over coastal central/southern CA later today into tonight. However, abundant capping and limited deep ascent should minimize inland thunderstorm potential, such that dry-thunderstorm highlights have not been included. Otherwise, no changes have been made to the ongoing forecast. ..Cohen.. 06/23/2017 .PREV DISCUSSION... /ISSUED 0145 AM CDT Fri Jun 23 2017/ ...Synopsis... Cyclonic flow aloft currently in place across the northern third of the CONUS will be maintained throughout the period as a series of shortwave troughs -- one currently moving through the northern Rockies and the other moving through the upper midwest -- progress through its base. Upper ridge extending from the Southwest northwestward to off the Pacific Northwest coast will remain largely unchanged. At the surface, a cold front will sweep southeastward/southward into the southern Plains and middle MS valley. Remnant of Tropical Storm Cindy will move into the lower OH river valley by the early afternoon before ejecting quickly northeastward as it interacts with the frontal boundary. Farther west, aforementioned cold front will move through eastern NM while the remaining portion of the Southwest and Great Basin remain hot and dry. Isolated thunderstorms are possible across the higher terrain of central NM but slow storm motion and precipitable water values greater than 0.90" should result in wetting rains. ...Mountains and western foothills of Kern, Los Angeles and San Bernardino counties in Southern CA... LAX-DAG gradient will likely be around 5 to 6 mb tomorrow afternoon, helping to foster some breezy westerly winds throughout the higher terrain and western foothills of Kern, Los Angeles, and San Bernardino counties. Warm and dry conditions are also expected with minimum RH values in the low teens. These windy and dry conditions amidst dry fuels will result in elevated to locally critical fire weather conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read mor […]

  • SPC Jun 23, 2017 1630 UTC Day 1 Convective Outlook
    on June 23, 2017 at 4:44 pm

    SPC 1630Z Day 1 Outlook Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1140 AM CDT Fri Jun 23 2017 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TN VALLEY TO THE DELMARVA/MID-ATLANTIC REGION... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN PLAINS/ARKLATEX... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF NM/SOUTHERN PLAINS TO APPALACHIANS/NEW ENGLAND... ...SUMMARY... Damaging wind gusts and a few tornadoes are possible this afternoon into evening from the Tennessee Valley toward parts of the Appalachians. A few severe storms with strong wind gusts and hail will also be possible across parts of the Northeast States and southern Plains. ...TN Valley vicinity... The remnants of Cindy will continue to spread east-northeastward through the afternoon and evening, with a corridor of low/mid-level winds preceding these remnants. A moist and increasingly uninhibited boundary layer this afternoon should allow for the intensification of a mixed mode of storms, including bands/clusters and the possibility of some cluster-preceding semi-discrete supercells. Given the magnitude of the low-level shear, especially from northern AL into middle/eastern TN and eastern KY, the potential will exist for a few tornadoes aside from some wind damage potential. Reference Mesoscale Discussion 1130 for additional short-term details. ...Middle/upper OH River Valley to Delmarva/Mid-Atlantic... As moisture continues to increase into the region, it appears that pockets of locally stronger heating will occur today ahead, and on the southern fringes, of upstream precipitation/thicker cloud cover. A steadily strengthening wind field will overspread the region through the afternoon and evening, with increasingly favorable wind profiles for organized storms including a few supercells/bows. Damaging winds should be the primary risk, but some hail and/or a tornado are possible as well. ...Southern Plains/Ark-La-Tex/Mid-South... Steep lapse rates and diabatic warming of the boundary layer will promote moderate instability in this region. Storms will likely develop along the south/southeastward-advancing cold front as well as over the higher terrain over NM/west TX. Additionally, ongoing storms across southwest MO may gradually increase in coverage/intensity as they progress southeastward into AR. The warm sector resides well south of the stronger winds aloft, but vertical shear will be supportive of multicells capable of producing a few strong to damaging wind gusts and marginally severe hail this afternoon into evening. ...Northern NY/New England... At least a few strong/severe thunderstorms are expected this afternoon across northeast NY into northern New England. ..Guyer/Gleason.. 06/23/2017 Read mor […]

  • SPC Jun 23, 2017 1300 UTC Day 1 Convective Outlook
    on June 23, 2017 at 1:14 pm

    SPC 1300Z Day 1 Outlook Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0808 AM CDT Fri Jun 23 2017 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM A PORTION OF THE GULF COAST STATES INTO THE TENNESSEE AND OHIO VALLEYS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE SOUTHERN PLAINS... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM A PORTION OF THE GULF COAST STATES INTO THE NORTHEAST STATES... ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF THE SOUTHERN PLAINS... CORRECTED FOR SLIGHT RISK UPGRADE OVER A PORTION OF THE SOUTHERN PLAINS ...SUMMARY... Thunderstorms may become capable of producing isolated strong to damaging wind gusts and a few tornadoes mainly this afternoon from a portion of the central Gulf Coast States northeastward into the central Appalachians. A few severe storms with strong wind gusts and hail will also be possible in the Northeast U.S. and southern Plains. ...Synopsis... The remnants of Cindy situated over western TN will become absorbed within a belt of stronger westerlies associated with an upper trough amplifying over the Great Lakes and Ohio Valley. This feature will subsequently accelerate east northeast through the TN Valley and into the southern Appalachians this afternoon and tonight before reaching the VA coast by the end of this period. At the surface a cold front stretching from the Great Lakes into the southern High Plains will continue southeastward and likely extend from New England into southwest TX by 12Z Saturday. ...Central Gulf Coast States and Tennessee Valley through the central Appalachians... Remnants of Cindy are transitioning to extratropical and will accelerate through the TN valley and southern Appalachians today. Belt of stronger winds aloft resulting from the strengthening gradient between Cindy and the amplifying northern-stream upper trough will spread through the TN and OH valleys. Immediately downstream from the circulation, a pronounced dry slot is evident from parts of TN through KY, and this should promote a period of boundary-layer destabilization, though MLCAPE will remain marginal /AOB 500 J/kg/ due to weak mid-level lapse rates. Nevertheless, convection within the associated convergence bands will likely increase this afternoon in a kinematic environment favorable for rotating updrafts. A few bowing segments and low-topped supercells are possible and will pose a risk for isolated strong to damaging wind gusts and a few tornadoes. The very marginal thermodynamic environment will probably remain a limiting factor over much of this region. ...Northeast States into the Ohio Valley... Winds aloft will strengthen over much of this area in association with the amplifying upstream trough with 0-6 km shear increasing to 35-40 kt. Widespread convection is ongoing from New York into New England within zone of isentropic ascent north of a warm front. Other convection is occurring farther south from OH to PA within deformation zone northeast of the remnants of Cindy as well as in association with a progressive mid-level shortwave trough. The atmosphere may undergo some destabilization where cloud breaks occur this afternoon, resulting in potential for a few organized strong to severe storms with damaging wind the main threat. While potential for slight risk may exist over a portion of this region, will maintain marginal risk category this update due to widespread clouds and uncertainty regarding evolution of the thermodynamic environment. ...Southern Plains... Steep lapse rates and diabatic warming of the boundary layer will promote moderate instability in this region. Storms will likely develop along southward-advancing cold front as well as over the higher terrain from parts of OK, TX and NM. The warm sector resides well south of the stronger winds aloft with weak shear supportive of multicells capable of producing a few strong to damaging wind gusts and marginally severe hail this afternoon into early evening. ..Dial/Picca.. 06/23/2017 Read mor […]

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