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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sat Aug 12 2023 Valid 122000Z - 131200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHEAST OHIO INTO PENNSYLVANIA AND WESTERN/SOUTHERN NEW YORK... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE GREAT PLAINS... ...SUMMARY... The most concentrated area of severe-thunderstorm threats into evening extends from northeast Ohio across parts of Pennsylvania and into central New York, with damaging to severe wind expected, along with large hail and a few tornadoes. Other severe storms capable of large hail and/or damaging gusts are possible across parts of the Great Plains into this evening. ...Great Lakes/Northeast area... The main changes for this area were to expand the Slight (level 2 of 5) and Marginal (level 1 of 5) risk areas southward a small amount across the New Jersey vicinity. This is to account for latest trends in observations and CAMs guidance. Otherwise, scattered severe storms continue across Tornado Watch 634 from northern OH into PA and western/central NY. Reference forthcoming MCD 1969 for short term severe potential. ...Mid-South and OH/TN Valley vicinity... Risk probabilities have been trimmed from portions of southeast MO/northeast AR into western/Middle TN and western/central KY where airmass modification by earlier convection has resulted in widespread MLCINH. Severe potential is expected to remain low across these areas the remainder of the period. ...Southern Appalachians/Carolinas... The Slight (level 2 of 5) risk has been trimmed across parts of TN/AL behind ongoing convective clusters. However, severe potential is expected to persist eastward into western/west-central NC/SC through this evening. Damaging gusts will be the main hazard expected with forward-propagating clusters. As a result, severe probabilities have been expanded eastward, with a gradual weakening trend expected as storms move into central NC/SC. ...SD/NE... A Slight risk (level 2 of 5) has been added to portions of southwest SD into north-central NE. Latest CAMs guidance suggest isolated supercells capable of large hail will develop and move east/southeast off the Black Hills late this afternoon/evening. Boundary-layer moisture will remain somewhat modest but will continue to increase through the evening, aiding in continued destabilization. With time, convection may grow upscale into a small bow as it tracks near the SD/NE border. This process should be aided by an increasing southerly low-level jet this evening. A few damaging/severe gusts may accompany this activity. Reference MCD 1968 for short term severe information. ...Southern Plains... The Marginal (level 1 of 2) risk has been expanded southward a small amount across OK. A differential heating zone and outflow from prior convection is oriented across the region and visible satellite and current radar indicate a band of developing storms from the southern TX Panhandle into southwest and central OK. Damaging gusts will be the main concern with this activity given generally weak vertical shear and a deeply mixed boundary-layer across the hot side of the differential heating zone. See MCD 1967 for more details in short term severe potential across the southern High Plains. ..Leitman.. 08/12/2023 .PREV DISCUSSION... /ISSUED 1123 AM CDT Sat Aug 12 2023/ ...Southern Great Lakes into the Northeast... Water-vapor imagery this morning shows a mid-level shortwave trough moving across the northern Great Lakes with a belt of stronger flow moving through the southern Great Lakes. Scattered thunderstorms will likely continue to develop through midday into the afternoon with the stronger storms becoming capable of a hail/wind threat. Forecast soundings show some low-level hodograph curvature, especially with northeast extent from northeast OH into PA and NY. Supercells will likely evolve from the stronger updrafts and pose a large to very large hail threat. It is with the supercells from the northern half of PA/northeast OH into southern NY where a tornado risk will seemingly focus this afternoon. As a surface cold front pushes east, additional storms are possible along the front and some of these will probably have an attendant hail/wind risk before weakening this evening. ...South-central Great Plains... In agreement with the previously issued forecast, expected widely scattered to scattered thunderstorms to initially develop over the eastern slopes of the Sangre de Cristos into the Raton Mesa region, and perhaps over intensely heated Plains areas of the northwestern TX Panhandle and northeastern NM. Activity then should move eastward and coalesce into one or more complexes, with severe wind the main concern, and isolated large hail possible. Upscale growth will probably occur during the evening with the severe wind risk spreading from southeastern CO and the OK/ northern TX Panhandles across southern KS and northern OK as it moves into richer moisture and large CAPE. In KS/OK, severe-gust potential should decrease with eastward extent tonight as activity encounters a gradually stabilizing boundary layer, but uncertainty exists over cold-pool strength vs. CINH and how fast the threat will diminish. ...TN Valley/Southeast... An ongoing thunderstorm cluster over KY/TN will continue to move east-southeast with scattered to numerous thunderstorms expected in the area centered over the TN Valley. Widespread 3000-4000 J/kg MLCAPE in areas slightly removed from ongoing midday storms will favor the potential for clusters to be capable of strongly water-loaded downdrafts. Damaging to locally severe gusts will be the main concern. ...North-central Plains... Isolated to scattered thunderstorms should develop this afternoon near the Black Hills vicinity. Supercells are possible given the strength of deep-layer shear. Isolated severe gusts and hail will be possible. This activity will diminish overnight and with southeastward extent, as the inflow layer stabilizes and becomes more elevated. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0210 PM CDT Sat Aug 12 2023 Valid 131200Z - 141200Z No changes to the ongoing forecast. ..Wendt.. 08/12/2023 .PREV DISCUSSION... /ISSUED 0155 AM CDT Sat Aug 12 2023/ ...Synopsis... Across the southern CONUS, high pressure will remain in place while intensifying across the West Coast. Very hot temperatures are expected beneath the ridge across TX and OK, into parts of the West, ahead of a cold front associated with a passing trough over the central CONUS. Elevated fire-weather conditions are possible across parts of the southern Plains and Cascades. Thunderstorms are also expected over much of the western Great Basin into portions of northern CA. ...Southern Plains... Similar to the previous days, extreme temperatures over 100 F are again expected beneath the upper ridge across parts of TX and OK. The glancing influence of the passing upper trough will help bolster surface winds by deepening a weak surface low across southwestern OK and western North TX. 10-15 mph southerly winds, with locally higher gusts, are expected along with the extreme temperatures and surface RH below 30%. Exceptionally dry fuels, along with the hot and breezy conditions, will support several hours of elevated to locally critical fire-weather conditions Sunday. A few thunderstorms are also possible late in the afternoon with gusty winds and occasional lightning. Storm coverage should remain isolated through the afternoon, before increasing in the evening ahead of an approaching cold front. As the cold front moves south, locally gusty and erratic winds may accompany the frontal passage, but rapidly recovering RH values and wetting rain potential behind it should diminish the fire-weather threat into early Monday. ...Northwest... Building high pressure near the coast and a deepening surface trough will likely support a few hours of dry and breezy conditions from southwest WA into portions of northern CA. Winds may briefly reach 15+ mph, especially through terrain-enhanced gaps of the Cascades and Coastal Ranges, concurrent with afternoon RH below 30-35%. Temporal and spatial coverage of more sustained elevated conditions is expected to remain low. Though, a few hours of locally elevated fire-weather concerns are possible within critically dry fuels. Low thunderstorm chances are expected across parts of northern CA Sunday afternoon through the overnight hours as monsoon moisture moves northward. Confidence in storm coverage is low with limited synoptic forcing for ascent. However, the increasing moisture and orographic circulations may support a few drier storms with the potential for lightning into areas of dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

000
ABPZ20 KNHC 121737
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat Aug 12 2023

For the eastern North Pacific...east of 140 degrees west longitude:

Central East Pacific (EP98):
Showers and thunderstorms continue to become better organized in
association with a low pressure system located several hundred
miles south-southwest of the southern tip of the Baja California
peninsula, and it appears that a tropical depression or tropical
storm could be forming. If these trends continue, advisories would
likely be initiated on this system later today. The low is expected
to move westward to west-northwestward at about 10 mph across the
central portion of the basin during the next few days.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 7 days...high...90 percent.

Western East Pacific (EP99):
A broad area of low pressure associated with a tropical wave is
producing a large area of disorganized showers and thunderstorms
well to the east-southeast of the Hawaiian Islands. Conditions
appear conducive for development of this system, and a tropical
depression is likely to form during the next few days while moving
toward the west or west-northwest at about 10 mph across the far
western portion of the basin, crossing into the Central Pacific
basin late Sunday.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...high...80 percent.

Off the Coast of Southern Mexico:
An area of low pressure is forecast to form offshore of Central
America and the southern coast of Mexico in a couple of days from
a tropical wave currently moving across the southern portion of
Central America. Environmental conditions are expected to be
conducive for development of this system, and a tropical depression
is likely to form during the early or middle part of next week while
it moves generally west-northwestward, roughly parallel to the coast
of southern and southwestern Mexico.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...high...80 percent.

$$
Forecaster Berg/Hagen

000
ABPZ20 KNHC 121737
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 AM PDT Sat Aug 12 2023

For the eastern North Pacific...east of 140 degrees west longitude:

Central East Pacific (EP98):
Showers and thunderstorms continue to become better organized in
association with a low pressure system located several hundred
miles south-southwest of the southern tip of the Baja California
peninsula, and it appears that a tropical depression or tropical
storm could be forming. If these trends continue, advisories would
likely be initiated on this system later today. The low is expected
to move westward to west-northwestward at about 10 mph across the
central portion of the basin during the next few days.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 7 days...high...90 percent.

Western East Pacific (EP99):
A broad area of low pressure associated with a tropical wave is
producing a large area of disorganized showers and thunderstorms
well to the east-southeast of the Hawaiian Islands. Conditions
appear conducive for development of this system, and a tropical
depression is likely to form during the next few days while moving
toward the west or west-northwest at about 10 mph across the far
western portion of the basin, crossing into the Central Pacific
basin late Sunday.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...high...80 percent.

Off the Coast of Southern Mexico:
An area of low pressure is forecast to form offshore of Central
America and the southern coast of Mexico in a couple of days from
a tropical wave currently moving across the southern portion of
Central America. Environmental conditions are expected to be
conducive for development of this system, and a tropical depression
is likely to form during the early or middle part of next week while
it moves generally west-northwestward, roughly parallel to the coast
of southern and southwestern Mexico.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...high...80 percent.

$$
Forecaster Berg/Hagen

Comal County also issued an emergency declaration on Aug. 11 due to steadily increasing fire danger during the last month. KENS 5 (San Antonio, Texas), Aug 11, 2023

The Bandera city council met and opted to close the city park and restrict swimming in the Medina River due to poor water quality. The river was no longer flowing, leaving the water in pools, in which organisms can multiply. The public was reminded to conserve water. KENS 5 (San Antonio, Texas), Aug 11, 2023

Farmers on either side of the Mississippi River in Minnesota and Wisconsin report only meager rainfall from early May through July 22. Crop germination may have failed or been inconsistent. The height of corn plants varies by several feet. Soybeans were smaller than usual. Herbicides did not get enough moisture to activate. La Crosse Tribune (Wis.), Aug 1, 2023

WW 0628 Status Updates
STATUS FOR WATCH 0628 HAS NOT BEEN ISSUED YET Read more

WW 628 SEVERE TSTM IA MN 112145Z - 120300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 628 NWS Storm Prediction Center Norman OK 445 PM CDT Fri Aug 11 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northern Iowa Southwest Minnesota * Effective this Friday afternoon and evening from 445 PM until 1000 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Scattered supercells may persist through late evening as the storms spread southeastward from southwest Minnesota toward northern Iowa. Large hail of 1-2 inches in diameter and wind damage with 60-70 mph winds will be the main severe threats. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 15 miles west northwest of Redwood Falls MN to 45 miles east southeast of Spencer IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 625...WW 626...WW 627... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 31030. ...Thompson Read more

WW 0625 Status Updates
STATUS REPORT ON WW 625 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1949 ..WEINMAN..08/11/23 ATTN...WFO...DMX...OAX...EAX...TOP... STATUS REPORT FOR WS 625 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC003-039-053-071-129-137-145-159-173-175-112240- IA . IOWA COUNTIES INCLUDED ARE ADAMS CLARKE DECATUR FREMONT MILLS MONTGOMERY PAGE RINGGOLD TAYLOR UNION KSC005-013-027-029-041-043-045-061-085-087-091-103-117-131-143- 149-161-177-197-201-209-112240- KS . KANSAS COUNTIES INCLUDED ARE ATCHISON BROWN CLAY CLOUD DICKINSON DONIPHAN DOUGLAS GEARY JACKSON JEFFERSON JOHNSON LEAVENWORTH MARSHALL NEMAHA OTTAWA POTTAWATOMIE RILEY SHAWNEE WABAUNSEE WASHINGTON WYANDOTTE Read more

WW 625 SEVERE TSTM IA KS MO NE 111735Z - 120100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 625 NWS Storm Prediction Center Norman OK 1235 PM CDT Fri Aug 11 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest Iowa Northeast Kansas Northwest Missouri Southeast Nebraska * Effective this Friday afternoon and evening from 1235 PM until 800 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 4 inches in diameter likely Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Scattered severe thunderstorms are forecast to develop this afternoon and persist into the early evening. The stronger storms will become supercellular and be capable of large to giant hail along with a risk for severe gusts. A localized risk for a tornado could develop during the early evening. The severe thunderstorm watch area is approximately along and 90 statute miles east and west of a line from 50 miles northwest of Lamoni IA to 20 miles west southwest of Topeka KS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 4 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Smith Read more

WW 0627 Status Updates
STATUS REPORT ON WW 627 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 45 SW STC TO 55 ESE BRD. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1951 ..WEINMAN..08/11/23 ATTN...WFO...ARX...MPX...DLH... STATUS REPORT FOR WS 627 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC005-089-191-112240- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE HOWARD WINNESHIEK MNC003-009-019-025-037-039-045-049-053-055-059-065-079-085-093- 095-099-109-115-123-131-139-141-143-145-147-157-161-163-169-171- 112240- MN . MINNESOTA COUNTIES INCLUDED ARE ANOKA BENTON CARVER CHISAGO DAKOTA DODGE FILLMORE GOODHUE HENNEPIN HOUSTON ISANTI KANABEC LE SUEUR MCLEOD MEEKER MILLE LACS MOWER OLMSTED PINE RAMSEY RICE SCOTT SHERBURNE SIBLEY Read more

WW 627 SEVERE TSTM IA MN WI 111925Z - 120300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 627 NWS Storm Prediction Center Norman OK 225 PM CDT Fri Aug 11 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Iowa Southeast and central Minnesota Western Wisconsin * Effective this Friday afternoon and evening from 225 PM until 1000 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Several strong to severe thunderstorm clusters are forecast to develop and pose a risk for large hail and damaging gusts. A few supercells are also possible and may pose a locally higher hail risk. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 55 miles northeast of Saint Cloud MN to 50 miles south southwest of La Crosse WI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 625...WW 626... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 29035. ...Smith Read more

WW 0626 Status Updates
STATUS REPORT ON WW 626 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SSW ANB TO 15 SSW CSG TO 45 WSW VDI. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1950 ..WEINMAN..08/11/23 ATTN...WFO...BMX...TAE...FFC... STATUS REPORT FOR WS 626 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC001-005-011-021-037-045-047-051-067-069-081-085-087-101-109- 113-123-112240- AL . ALABAMA COUNTIES INCLUDED ARE AUTAUGA BARBOUR BULLOCK CHILTON COOSA DALE DALLAS ELMORE HENRY HOUSTON LEE LOWNDES MACON MONTGOMERY PIKE RUSSELL TALLAPOOSA GAC007-017-019-037-061-071-075-081-095-099-155-177-201-205-239- 243-259-261-273-277-287-307-315-321-112240- GA . GEORGIA COUNTIES INCLUDED ARE BAKER BEN HILL BERRIEN CALHOUN CLAY COLQUITT COOK CRISP DOUGHERTY Read more

WW 626 SEVERE TSTM AL GA 111910Z - 120000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 626 NWS Storm Prediction Center Norman OK 310 PM EDT Fri Aug 11 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeastern Alabama Southwestern Georgia * Effective this Friday afternoon and evening from 310 PM until 800 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible Isolated large hail events to 1 inch in diameter possible SUMMARY...Thunderstorms will continue to develop and intensify this afternoon across the watch area. Small thunderstorm clusters will pose a risk for damaging gusts through the afternoon and into the early evening. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 40 miles north northwest of Troy AL to 40 miles northeast of Moultrie GA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 625... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 31020. ...Smith Read more

MD 1951 CONCERNING SEVERE THUNDERSTORM WATCH 627... FOR SOUTHEASTERN MN AND WESTERN WI
Mesoscale Discussion 1951 NWS Storm Prediction Center Norman OK 0400 PM CDT Fri Aug 11 2023 Areas affected...southeastern MN and western WI Concerning...Severe Thunderstorm Watch 627... Valid 112100Z - 112300Z The severe weather threat for Severe Thunderstorm Watch 627 continues. SUMMARY...The severe weather threat is increasing across WW 627. Damaging wind gusts and large hail are possible. DISCUSSION...Multiple strong/severe thunderstorms are ongoing across the northern periphery of WW 627. Several wind events have been reported -- including a measured 76 mph gust at in Kanabec County (KJMR) -- as well as hailstones up to 2" in diameter. These storms have evolved along/just ahead of a cold front and maintained semi-discrete/supercellular structures for the last couple of hours. Additional convection initiation is now underway to the southwest of these damaging storms. The downstream environment is characterized by MLCAPE around 1500 J/kg and bulk shear around 50 kts. With long and straight northwesterly hodographs (currently observed at KMPX), this environment will be favorable for splitting supercell structures capable of producing severe hail and wind gusts. Both of these risks should maximize over the Twin Cities metro and the southeastern vicinity this afternoon. Thereafter, a gradual transition to a primarily wind threat is expected this evening as the system congeals along the cold front. ..Flournoy.. 08/11/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...ARX...MPX...DMX... LAT...LON 44309484 44759493 45279453 45919376 46089292 46009220 45519129 44449075 43419079 43059142 43249268 43729398 44309484 Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0346 PM CDT Fri Aug 11 2023 Valid 131200Z - 191200Z Upper-level ridging will be the dominant feature across the West through most of the extended period. A weak, remnant tropical low will also be present off the west coast and will generally move northwestward until eventually phasing with the stronger westerlies perhaps by the end of next weekend. Cold fronts are expected to move into the southern Plains both late this weekend and late next week. ...Northern California into the Northwest... The primary concern during the extended period will be the evolution of the weak, tropical remnant low currently off the California coast. This feature is forecast to slowly retrograde northwestward with time. A few perturbations within this circulation may spark isolated thunderstorm development in parts of northern California into Oregon. Some of these storms may be on the drier side, but storms motions may also be slow. Though predictability is low, current forecast data suggest northern California will see relatively greater thunderstorm coverage this Monday with Oregon increasing on Tuesday. While this low retrogrades west, a lull in thunderstorm activity is possible. Later in the week, model guidance suggests that cyclonic flow will increase off the Northwest coast. At that time, the weak upper low is expected to phase with the broader upper trough. Some thunderstorm risk would be possible late next week in the northern California and parts of the Northwest. Again, predictability is quite low this far in advance to highlight any dry thunderstorm risk. As mid-level winds increase along the Canadian border into northern Washington on Tuesday, there is some potential for dry and windy conditions within the Cascade gaps into the Columbia Basin as a thermal surface pressure trough develops in the Basin. Guidance has not been overly consistent in this signal so probabilities will be withheld for now. ...Texas... Winds are anticipated to be weaker over the next several days. Some increase could occur as a cold front approaches this Sunday. As the front passes, winds will generally turn more northerly into the middle of next week. Another front is currently forecast to move into the southern Plains towards the end of next week. With hot conditions expected ahead of the front, it is possible that isolated thunderstorms could develop during the afternoon perhaps Thursday/Friday. Some lighting could occur at least outside precipitation cores and area fuels would certainly continue to support ignitions. The overall potential for critical fire weather remains too low for highlights, however. ...Northern Rockies... A strong trough will move through the northern Rockies into the northern Plains around the middle of next week. A strong surface pressure gradient will develop along with a deepening surface low in the northern Plains. Strong downslope winds are probable along the lee of the terrain in western Montana. Some precipitation is possible in the area with a cold front moving through the area late Saturday into Sunday. Probabilities will be withheld for now given some potential impact on fuels from this precipitation. ..Wendt.. 08/11/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1950 CONCERNING SEVERE THUNDERSTORM WATCH 626... FOR PORTIONS OF EASTERN AL AND WESTERN GA
Mesoscale Discussion 1950 NWS Storm Prediction Center Norman OK 0342 PM CDT Fri Aug 11 2023 Areas affected...portions of eastern AL and western GA Concerning...Severe Thunderstorm Watch 626... Valid 112042Z - 112245Z The severe weather threat for Severe Thunderstorm Watch 626 continues. SUMMARY...Strong/severe thunderstorms are expected to persist across WW 626 for the next few hours. Damaging wind gusts and small hail will be the primary threats. DISCUSSION...Multiple thunderstorm complexes are currently ongoing in eastern AL and western GA in WW 626. They have been associated with both strong/severe wind (primarily tree and power line damage) and quarter-size hail reports. The leading storm -- currently located in Stewart County -- featured a robust mesocyclone for around an hour before weakening to its current state. The complex in its wake also contained multiple weaker low-level mesocyclones early in its evolution, likely due to its formation near/along the remnant outflow from the morning QLCS (now moving offshore in SC). The environment ahead of these thunderstorms remains favorable for damaging wind and hail production. The latest VADs from KEOX depict modest low-level shear (around 15-20 kts in the 0-3-km layer) amidst ample MLCAPE (3000+ J/kg). Bulk shear is expected to remain more marginal however, around 15 kts. This should favor a gradually congealing system during the next couple of hours. Current storm-scale trends support this evolution, depicting spreading outflow and cold-pool deficits around 15 degrees F. This should yield a gradual transition from a mixed hail/wind threat to more of a damaging-wind threat for the next few hours across WW 626. ..Flournoy.. 08/11/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JAX...FFC...TAE...BMX...MOB... LAT...LON 32698620 32578523 32188429 31718320 31348303 30898324 30808406 30968545 31358615 31888638 32418646 32698620 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Fri Aug 11 2023 Valid 112000Z - 121200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MIDDLE MISSOURI VALLEY AREA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER MISSISSIPPI VALLEY VICINITY...PARS OF THE SOUTHEAST...AND THE SOUTHERN LOWER MICHIGAN AREA... ...SUMMARY... Scattered severe thunderstorms will continue across the lower Missouri Valley late this afternoon through the evening. Supercells capable of very large hail, severe gusts, and perhaps a tornado are the primary threats. Severe storms are also ongoing across pars of the Upper Mississippi Valley, and the Southeast, and may evolve over Lower Michigan as well. ...Discussion... Only minor line adjustments are being made to the ongoing outlook at this time, with the most substantial change being to expand SLGT risk into parts of southeastern Alabama, where WW 626 remains in effect and several strong storms continue moving southeastward. Watches also remain in effect across parts of the Mid Missouri Valley, and the Upper Mississippi Valley at this time. ..Goss.. 08/11/2023 .PREV DISCUSSION... /ISSUED 1149 AM CDT Fri Aug 11 2023/ ...Central Great Plains east into the lower OH Valley... Complicated forecast scenario today with a small MCS moving southeast over south-central IL. It remains unclear whether a rejuvenation or strengthening of this complex will occur as the boundary layer continues to destabilize to its southeast across the lower Wabash Valley. Isolated damaging gusts appear to be the primary risk. Farther west, mid-level convection has been noted across parts of the central Great Plains late this morning. This is occurring on the northeast periphery of steep 700-500 mb lapse rates. Going forward this afternoon, models show a consensus in showing thunderstorms developing by mid afternoon from northern KS into northwest MO and perhaps southern IA where 3000+ J/kg of MLCAPE is forecast. Strengthening west-northwesterly flow with height will elongate hodographs and favor supercells. Large to very large hail and severe gusts will be the primary threats. A tornado is possible, especially where surface temperature-dewpoint spreads are near 20 deg F. Upscale growth is forecast this evening with a thunderstorm complex perhaps moving southeastward into the lower MO Valley overnight. Have reduced severe probabilities across parts of the IL in wake of the morning MCS where forcing mechanisms to initiate storms are nebulous and highly uncertain. ...Upper MS Valley... A mid-level speed max will approach the region this afternoon. Strong deep shear and weaker buoyancy are expected, but with instability still sufficient to support at least isolated strong-severe convection. MLCAPE 1000-2000 J/kg in parts of central/eastern MN and northern WI, under the strongest cooling aloft preceding the mid/upper trough. 40-50 kt effective-shear magnitudes are progged over the upper Mississippi Valley region as well. Large hail and damaging gusts are the primary risks with these storms. Some of this activity may move as far southeast as southern WI and northern IL late tonight. ...Southern Great Lakes... A disturbance moving east-southeast through the Great Lakes will probably aid in scattered thunderstorms developing this afternoon. Although heating will be tempered somewhat by a cirrus canopy this afternoon, model forecast soundings show moderate buoyancy (1000-2000 J/kg MLCAPE) amidst a veering and strengthening wind profile with height. Have added a small Slight Risk for the possibility for organized storms to pose a risk for damaging gusts, isolated large hail, and perhaps a tornado or two mainly late this afternoon through the early evening. ...Southeast states... Ongoing cluster of thunderstorms over the Savannah River Valley will continue to move east into the coastal plain of SC later this afternoon. Very moist low levels and temperatures warming into 90s south and east of early day storms will favor strong instability developing by early to mid afternoon. Water-loaded downdrafts will potentially yield strong and locally severe microbursts capable of wind damage. Have upgraded southern GA into southern coastal SC into a categorical Slight Risk where model guidance shows higher storm coverage and greater buoyancy (reference the 12z TLH raob) resides. This activity will likely diminish during the evening. ...Northwest TX/southwest OK... Intense heating will again promote temperatures warming well into the 100s deg F by late afternoon to near or at convective temperatures. Models indicate at least a few storms developing during the late afternoon/early evening. Very steep lapse rates will favor evaporative cooling and the potential for isolated severe gusts. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0209 PM CDT Fri Aug 11 2023 Valid 121200Z - 131200Z The overall pattern will be quite similar tomorrow in Texas as it is today. Given the state of fuels and current observations, greater weight was placed on the drier model solutions and the elevated area was expanded southward. ..Wendt.. 08/11/2023 .PREV DISCUSSION... /ISSUED 0158 AM CDT Fri Aug 11 2023/ ...Synopsis... Mid-level high pressure is forecast to remain in place across the central US while also intensifying over the western US through much of Day2/Saturday. Very warm conditions are likely over the southern Plains as monsoon moisture moves north across the Great Basin and Southwest. Hot and breezy conditions will support fire-weather concerns over parts of TX and OK, with thunderstorm chances and local fire-weather potential increasing across parts of the Northwest. ...Central TX... Another day of extreme temperatures is expected beneath the ridge focused over portions of the southern Plains. Widespread surface temperatures exceeding 100 F will continue to support extremely volatile fuels across parts of central TX and southwest OK. Dry southerly winds enhanced by a lee trough and thermal low over OK will reach 10-15 mph and higher gusts into the evening. Several hours of elevated to locally critical fire-weather conditions are expected given the volatile fuels and extremely warm/breezy conditions. ...Northern Great Basin... Monsoon moisture is forecast to slowly increase across portions of the northern Great Basin through D2/Saturday. Area model soundings show PWAT values approaching 0.5-0.6 inches across parts of northern NV, into CA, and far southern OR. While synoptic lift will be weak, isolated thunderstorms may develop along the higher terrain of the Sierra and far southern Cascades. Warm and dry surface conditions suggest any storms that do form will be high-based with low wetting rainfall potential. A few dry lightning strikes are possible within mostly receptive fuels. However, with only weak synoptic forcing present, confidence in sufficient storm coverage for IsoDryT highlights is very low. ...Northwest... Weak onshore flow from eastern Pacific high pressure will help drive northerly flow over parts of southwest WA and northwest/west-central OR. Surface wind gusts of 15-25 mph are possible, especially within terrain-enhanced areas of the central Cascades and Coastal Ranges. While surface RH values are not expected to be overly dry given the onshore wind component, minimum RH values below 35%, along with the gusty winds, may support a few hours of locally elevated fire-weather potential within dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more